How to use the parso.tree.search_ancestor function in parso

def _convert_names(self, names):
        for name in names:
            param = search_ancestor(name, 'param')
            if param:
                yield self.param_name(self.context, name)
            else:
                yield TreeNameDefinition(self.context, name)

def _get_param_node(self):
        return search_ancestor(self.tree_name, 'param')

def _get_global_filters_for_name(context, name_or_none, position):
    # For functions and classes the defaults don't belong to the
    # function and get inferred in the value before the function. So
    # make sure to exclude the function/class name.
    if name_or_none is not None:
        ancestor = search_ancestor(name_or_none, 'funcdef', 'classdef', 'lambdef')
        lambdef = None
        if ancestor == 'lambdef':
            # For lambdas it's even more complicated since parts will
            # be inferred later.
            lambdef = ancestor
            ancestor = search_ancestor(name_or_none, 'funcdef', 'classdef')
        if ancestor is not None:
            colon = ancestor.children[-2]
            if position is not None and position < colon.start_pos:
                if lambdef is None or position < lambdef.children[-2].start_pos:
                    position = ancestor.start_pos

    return get_global_filters(context, position, name_or_none)

def is_import(self):
        imp = search_ancestor(self.tree_name, 'import_from', 'import_name')
        return imp is not None

def get_param(self):
        params = self.parent_context.get_params()
        param_node = search_ancestor(self.tree_name, 'param')
        return params[param_node.position_index]

def get_param(self):
        params = self.parent_context.get_params()
        param_node = search_ancestor(self.tree_name, 'param')
        return params[param_node.position_index]

def _get_global_filters_for_name(context, name_or_none, position):
    # For functions and classes the defaults don't belong to the
    # function and get inferred in the value before the function. So
    # make sure to exclude the function/class name.
    if name_or_none is not None:
        ancestor = search_ancestor(name_or_none, 'funcdef', 'classdef', 'lambdef')
        lambdef = None
        if ancestor == 'lambdef':
            # For lambdas it's even more complicated since parts will
            # be inferred later.
            lambdef = ancestor
            ancestor = search_ancestor(name_or_none, 'funcdef', 'classdef')
        if ancestor is not None:
            colon = ancestor.children[-2]
            if position is not None and position < colon.start_pos:
                if lambdef is None or position < lambdef.children[-2].start_pos:
                    position = ancestor.start_pos

    return get_global_filters(context, position, name_or_none)

result = None
    if is_scope(flow):
        # Check for asserts.
        module_node = flow.get_root_node()
        try:
            names = module_node.get_used_names()[search_name.value]
        except KeyError:
            return None
        names = reversed([
            n for n in names
            if flow.start_pos <= n.start_pos < (pos or flow.end_pos)
        ])

        for name in names:
            ass = search_ancestor(name, 'assert_stmt')
            if ass is not None:
                result = _check_isinstance_type(context, ass.assertion, search_name)
                if result is not None:
                    return result

    if flow.type in ('if_stmt', 'while_stmt'):
        potential_ifs = [c for c in flow.children[1::4] if c != ':']
        for if_test in reversed(potential_ifs):
            if search_name.start_pos > if_test.end_pos:
                return _check_isinstance_type(context, if_test, search_name)
    return result

elif node_type == 'dotted_name':  # Is a decorator.
            index = par.children.index(name)
            if index > 0:
                new_dotted = deep_ast_copy(par)
                new_dotted.children[index - 1:] = []
                values = context.infer_node(new_dotted)
                return unite(
                    value.goto(name, name_context=context)
                    for value in values
                )

        if node_type == 'trailer' and par.children[0] == '.':
            values = infer_call_of_leaf(context, name, cut_own_trailer=True)
            return values.goto(name, name_context=context)
        else:
            stmt = search_ancestor(
                name, 'expr_stmt', 'lambdef'
            ) or name
            if stmt.type == 'lambdef':
                stmt = name
            return context.goto(name, position=stmt.start_pos)