How to use the icecream.icecream.NoSourceAvailableError function in icecream

#
    #   class Foo:
    #       blah = ic
    #   Foo.blah()
    #
    parentBlockSource = textwrap.dedent(parentBlockSource)
    potentialCalls = [
        node for node in ast.walk(ast.parse(parentBlockSource))
        if isAstNodeIceCreamCall(node, icNames, icMethod) and
        linenoRelativeToParent in getAllLineNumbersOfAstNode(node)]

    if not potentialCalls:
        # TODO(grun): Add note that to NoSourceAvailableError that this
        # situation can occur when the underlying source changed during
        # execution.
        raise NoSourceAvailableError()

    endLine = lineno - parentBlockStartLine + 1
    startLine = min(call.lineno for call in potentialCalls)
    lines = parentBlockSource.splitlines()[startLine - 1: endLine]

    # inspect's lineno attribute doesn't point to the closing right parenthesis
    # if the closing right parenthesis is on its own line without any
    # arguments. E.g.
    #
    #  ic(1,
    #     2  <--- inspect's reported lineno.
    #     )  <--- Should be the reported lineno.
    #
    # Detect this situation and add the missing right parenthesis.
    if isCallStrMissingClosingRightParenthesis('\n'.join(lines).strip()):
        lines.append(')')

# which bypasses getblock().
    #
    # Also, the errors raised differ between Python2 and Python3 . In Python2,
    # inspect.findsource() and inspect.getsource() raise IOErrors. In Python3,
    # inspect.findsource() and inspect.getsource() raise OSErrors.
    try:
        if code.co_name == '':  # Module -> use workaround above.
            parentBlockStartLine = 1
            lines = inspect.findsource(code)[0]  # Raises [IO/OS]Error.
            parentBlockSource = ''.join(lines)
        else:  # Not a module -> use inspect.getsource() normally.
            parentBlockStartLine = code.co_firstlineno
            parentBlockSource = inspect.getsource(code)  # Raises [IO/OS]Error.
    except (IOError, OSError) as err:
        if 'source code' in err.args[0]:
            raise NoSourceAvailableError()
        else:
            raise

    lineno = inspect.getframeinfo(callFrame)[1]
    linenoRelativeToParent = lineno - parentBlockStartLine + 1

    # There could be multiple ic() calls on the same line(s), like
    #
    #   ic(1); ic(2); ic(3,
    #       4,
    #       5); ic(6)
    #
    # so include all of them. Which invocation is the appropriate one will be
    # determined later via bytecode offset calculations.
    #
    # TODO(grun): Support invocations of ic() where ic() is an attribute chain

def __call__(self, *args):
        if self.enabled:
            callFrame = inspect.currentframe().f_back
            try:
                out = self._format(callFrame, *args)
            except NoSourceAvailableError as err:
                prefix = callOrValue(self.prefix)
                out = prefix + 'Error: ' + err.infoMessage
            self.outputFunction(out)

        if not args:  # E.g. ic().
            passthrough = None
        elif len(args) == 1:  # E.g. ic(1).
            passthrough = args[0]
        else:  # E.g. ic(1, 2, 3).
            passthrough = args

        return passthrough