How to use the bokeh.models.widgets.Button function in bokeh

def __init__(self):
        note = Div(text="<b>NOTE</b>: Each plan may only have one protocol assigned. "
                        "Updating database will overwrite any existing data.", width=700)
        self.update_checkbox = CheckboxGroup(labels=["Only update plans in table."], active=[0])

        self.toxicity = []  # Will be used to link to Toxicity tab

        self.source = ColumnDataSource(data=dict(mrn=['']))
        self.source.selected.on_change('indices', self.source_listener)

        self.clear_source_selection_button = Button(label='Clear Selection', button_type='primary', width=150)
        self.clear_source_selection_button.on_click(self.clear_source_selection)

        self.protocol = Select(value='', options=[''], title='Protocols:')
        self.physician = Select(value='', options=[''], title='Physician:', width=150)

        self.date_filter_by = Select(value='None', options=['None', 'sim_study_date', 'import_time_stamp'],
                                     title='Date Filter Type:', width=150)
        self.date_filter_by.on_change('value', self.date_ticker)
        self.date_start = DatePicker(title='Start Date:', width=200)
        self.date_start.on_change('value', self.date_ticker)
        self.date_end = DatePicker(title='End Date:', width=200)
        self.date_end.on_change('value', self.date_ticker)

        self.update_protocol_options()
        self.update_physician_options()

f2              = Frame("F2")
f1.tri.data     = dict(x = [0.1,0.8], y = [0.1,0.1], size = [tri_size,tri_size])
#seg             = dict(x0=[0.095,0.097,0.099,0.101,0.103,0.105],
#                x1=[0.095+shift,0.097+shift,0.099+shift,0.101+shift,0.103+shift,0.105+shift],
#                y0=[0.09]*5, y1=[0.088]*5)
t_line          = dict(x=[0.7,0.9], y=[ground,ground])

#sliders:
mag_start   = -100
mag_end     = 100
mag_val     = 0
mag_slider  = Slider(title="Kraftbetrag", value=mag_val, start=mag_start, end=mag_end, step=1)

#Toggle button:
button = Button(label="Save", button_type="success")
rbutton = Button(label="Reset", button_type="success")
loc_start = 0
loc_end = 100
loc_val = 50
loc_slider = Slider(title="Kraftposition", value=loc_val, start=loc_start, end=loc_end, step=1)
#p2loc_slider = Slider(title=f2.name + " Kraftposition", value=loc_val, start=loc_start, end=loc_end, step=1)


def create_orig(o):
    x = [o.x0,o.x0,o.xf,o.xf]
    y = [o.y0,o.yf,o.yf,o.y0]
    o.pts.data = dict(x = x, y = y )


def create_prof(f):
    paramInt = f.get_param()
    i = f.get_mag()

width=100)
        self.time_prev_button.on_click(self.on_time_prev)
        
        # Create time selection dropdown widget
        self.time_list = sorted([time_str + 'UTC' for time_str in 
                                 self.datasets['simim']['data'].get_data('I').keys()
                                 if time_str in self.datasets['simim']['data'].get_data('I').keys()])
        time_dd_list = [(k1, k1) for k1 in self.time_list]
        self.data_time_dd = bokeh.models.widgets.Dropdown(label='Time',
                                                          menu=time_dd_list,
                                                          button_type='warning',
                                                          width=300)
        self.data_time_dd.on_change('value', self.on_data_time_change)

        # Create next timestep button widget
        self.time_next_button = bokeh.models.widgets.Button(label='Next',
                                                            button_type='warning',
                                                            width=100)
        self.time_next_button.on_click(self.on_time_next)

        # Set layout rows for widgets
        self.time_row = \
            bokeh.layouts.row(self.time_prev_button,
                              bokeh.models.Spacer(width=20, height=60),
                              self.data_time_dd,
                              bokeh.models.Spacer(width=20, height=60),
                              self.time_next_button)
        self.major_config_row = bokeh.layouts.row(self.wavelength_dd)
        self.plots_row = bokeh.layouts.row(*self.bokeh_imgs)
        self.info_row = bokeh.layouts.row(bokeh.models.Spacer(width=400, height=100), 
                                          self.colorbar_div,
                                          bokeh.models.Spacer(width=400, height=100))

#Magnitude of load slider:
mag_start   = -100
mag_end     = 100
mag_val     = 0
mag_slider  = Slider(title="Magnitude", value=mag_val,
    start=mag_start, end=mag_end, step=1)

#Position of load slider:
loc_start = 0
loc_end = 100
loc_val = 50
loc_slider = Slider(title="Position", value=loc_val,
    start=loc_start, end=loc_end, step=1)

#Toggle buttons:
button = Button(label="Save Deformed Frame", button_type="success")             #Button to save the deformed frain. Calls function
rbutton = Button(label="Reset", button_type="success")                          #Reset button. Calls init function


################################################################################
###Functions
################################################################################

def create_orig(o):
    '''Creates stationary original frame'''
    x = [o.x0,o.x0,o.xf,o.xf]
    y = [o.y0,o.yf,o.yf,o.y0]
    o.pts.data = dict(x = x, y = y)



def update_fun(attr,old,new):

text_node = Div(text="Node:", width=100, height=20)
    text_joints = Div(text="Joints:", width=100, height=20)
    text_elements = Div(text="Line elements:", width=100, height=20)
    text_loads = Div(text="Loads:", width=100, height=20)

    b_height = 50
    b_line_width = 72

    # configure buttons for mechanical supports
    button_support_clamped = Button(label="", css_classes=[eLnum.ElSupEnum.SUPPORT_CLAMPED.name], width=b_height,
                                    height=b_height)
    curr_doc.buttons[eLnum.ElSupEnum.SUPPORT_CLAMPED.value] = button_support_clamped
    button_support_clamped.on_click(partial(vis_cbs.cb_button_element_click, curr_doc=curr_doc,
                                            button_enum=eLnum.ElSupEnum.SUPPORT_CLAMPED))

    button_support_normal = Button(label="", css_classes=[eLnum.ElSupEnum.SUPPORT_NORMAL_FORCE.name], width=b_height,
                                   height=b_height)
    curr_doc.buttons[eLnum.ElSupEnum.SUPPORT_NORMAL_FORCE.value] = button_support_normal
    button_support_normal.on_click(partial(vis_cbs.cb_button_element_click, curr_doc=curr_doc,
                                           button_enum=eLnum.ElSupEnum.SUPPORT_NORMAL_FORCE))

    button_support_transverse = Button(label="", css_classes=[eLnum.ElSupEnum.SUPPORT_TRANSVERSE_FORCE.name],
                                       width=b_height, height=b_height)
    curr_doc.buttons[eLnum.ElSupEnum.SUPPORT_TRANSVERSE_FORCE.value] = button_support_transverse
    button_support_transverse.on_click(partial(vis_cbs.cb_button_element_click, curr_doc=curr_doc,
                                               button_enum=eLnum.ElSupEnum.SUPPORT_TRANSVERSE_FORCE))

    button_support_fixed_conti = Button(label="", css_classes=[eLnum.ElSupEnum.SUPPORT_FIXED_CONTINUOUS.name],
                                        width=b_height, height=b_height)
    curr_doc.buttons[eLnum.ElSupEnum.SUPPORT_FIXED_CONTINUOUS.value] = button_support_fixed_conti
    button_support_fixed_conti.on_click(
        partial(vis_cbs.cb_button_element_click, curr_doc=curr_doc, button_enum=eLnum.ElSupEnum.SUPPORT_FIXED_CONTINUOUS))

def button_save_table(table):
    """Button to save selected data table as csv.

    Notes
    -----
    * Does not work for column values containing tuples (like 'neighbors')
    * Currently columns being saved are hard coded in the javascript callback
    * Available styles: 'default', 'primary', 'success', 'warning', 'danger'
    """
    button = Button(label="Download selected data", button_type="success")
    button.callback = CustomJS(args=dict(source=table.source),
                               code=open(join(dirname(__file__),
                                              "download_data.js")).read())
    return widgetbox(button)

def _create_widgets(self):
        """
        Main setup function for creating GUI widgets for user feedback.
        """
        input_fields, self.feedback_dict = \
            self._process_config(self.config_path)

        self.submit_button = bokeh.models.widgets.Button(label='Submit',
                                                         button_type='warning',
                                                         width=BUTTON_WIDTH)
        self.submit_button.on_click(self._on_submit)
        self.feedback_layout = bokeh.layouts.column(input_fields,
                                                    self.submit_button)

self.tv_data = {}

        roi_colors = plot_colors.cnames.keys()
        roi_colors.sort()
        roi_viewer_options = [''] + sources.dvhs.data['mrn']
        self.mrn_select = Select(value='', options=roi_viewer_options, width=200, title='MRN')
        self.study_date_select = Select(value='', options=[''], width=200, title='Sim Study Date')
        self.uid_select = Select(value='', options=[''], width=400, title='Study Instance UID')
        self.roi_select = {str(i): Select(value='', options=[''], width=200, title='ROI %s Name' % i) for i in range(1, 6)}

        colors = ['blue', 'green', 'red', 'orange', 'lightgreen']
        self.roi_select_color = {str(i): Select(value=colors[i-1], options=roi_colors, width=150, title='ROI %s Color' % i) for i in range(1, 6)}
        self.slice_select = Select(value='', options=[''], width=200, title='Slice: z = ')
        self.previous_slice = Button(label="<", button_type="primary", width=50)
        self.next_slice = Button(label=">", button_type="primary", width=50)
        self.flip_x_axis_button = Button(label='Flip X-Axis', button_type='primary', width=100)
        self.flip_y_axis_button = Button(label='Flip Y-Axis', button_type='primary', width=100)
        self.plot_tv_button = Button(label='Plot TV', button_type='primary', width=100)

        self.mrn_select.on_change('value', self.mrn_ticker)
        self.study_date_select.on_change('value', self.study_date_ticker)
        self.uid_select.on_change('value', self.uid_ticker)
        self.slice_select.on_change('value', self.slice_ticker)

        self.previous_slice.on_click(self.go_to_previous_slice)
        self.next_slice.on_click(self.go_to_next_slice)
        self.flip_x_axis_button.on_click(self.flip_x_axis)
        self.flip_y_axis_button.on_click(self.flip_y_axis)
        self.plot_tv_button.on_click(self.plot_tv)

        self.fig = figure(plot_width=825, plot_height=600, match_aspect=True,
                          tools="pan,wheel_zoom,reset,crosshair,save")

'''
        '''
        # Create variable selection dropdown widget
        variable_menu_list = \
            create_dropdown_opt_list_from_dict(VARIABLE_DD_DICT,
                                               self.plot_names)
        label = Label("Variable: {}")
        self.model_variable_drop_down = \
            bokeh.models.widgets.Dropdown(label=label.first(variable_menu_list),
                                          menu=variable_menu_list)
        label.listen_to(self.model_variable_drop_down)
        self.model_variable_drop_down.on_change('value', self.on_var_change)

        # Create previous timestep button widget
        self.time_previous_button = \
            bokeh.models.widgets.Button(label='Previous validity time')
        self.time_previous_button.on_click(self.on_time_prev)

        # Create next timestep button widget
        self.time_next_button = \
            bokeh.models.widgets.Button(label='Next validity time')
        self.time_next_button.on_click(self.on_time_next)

        # select model run
        label = Label("Model run: {}")
        model_run_list = create_model_run_list(self.datasets.keys())
        self.model_run_drop_down = \
            bokeh.models.widgets.Dropdown(label=label.first(model_run_list),
                                          menu=model_run_list)
        label.listen_to(self.model_run_drop_down)
        self.model_run_drop_down.on_change('value', self._on_model_run_change)

else:
            self.dvh_review_rois = ['']

        # Add Current row to source
        self.add_endpoint_row_button = Button(label="Add Endpoint", button_type="primary", width=200)
        self.add_endpoint_row_button.on_click(self.add_endpoint)

        self.ep_row = Select(value='', options=[''], width=50, title="Row")
        self.ep_options = ["Dose (Gy)", "Dose (%)", "Volume (cc)", "Volume (%)"]
        self.select_ep_type = Select(value=self.ep_options[0], options=self.ep_options, width=180, title="Output")
        self.select_ep_type.on_change('value', self.select_ep_type_ticker)
        self.ep_text_input = TextInput(value='', title="Input Volume (cc):", width=180)
        self.ep_text_input.on_change('value', self.ep_text_input_ticker)
        self.ep_units_in = RadioButtonGroup(labels=["cc", "%"], active=0, width=100)
        self.ep_units_in.on_change('active', self.ep_units_in_ticker)
        self.delete_ep_row_button = Button(label="Delete", button_type="warning", width=100)
        self.delete_ep_row_button.on_click(self.delete_ep_row)

        tools = "pan,wheel_zoom,box_zoom,reset,crosshair,save"
        self.plot = figure(plot_width=1050, plot_height=500, tools=tools, active_drag="box_zoom")
        self.plot.min_border_left = options.MIN_BORDER
        self.plot.min_border_bottom = options.MIN_BORDER
        self.plot.add_tools(HoverTool(show_arrow=False, line_policy='next',
                                      tooltips=[('Label', '@mrn @roi_name'),
                                                ('Dose', '$x'),
                                                ('Volume', '$y')]))
        self.plot.xaxis.axis_label_text_font_size = options.PLOT_AXIS_LABEL_FONT_SIZE
        self.plot.yaxis.axis_label_text_font_size = options.PLOT_AXIS_LABEL_FONT_SIZE
        self.plot.xaxis.major_label_text_font_size = options.PLOT_AXIS_MAJOR_LABEL_FONT_SIZE
        self.plot.yaxis.major_label_text_font_size = options.PLOT_AXIS_MAJOR_LABEL_FONT_SIZE
        self.plot.yaxis.axis_label_text_baseline = "bottom"
        self.plot.lod_factor = options.LOD_FACTOR  # level of detail during interactive plot events