def by_external_connection_id(self,external_connection_id: str) -> ExternalConnectionItemRequestBuilder:
        """
        Provides operations to manage the collection of externalConnection entities.
        param external_connection_id: The unique identifier of externalConnection
        Returns: ExternalConnectionItemRequestBuilder
        """
        if external_connection_id is None:
            raise TypeError("external_connection_id cannot be null.")
        from .item.external_connection_item_request_builder import ExternalConnectionItemRequestBuilder

        url_tpl_params = get_path_parameters(self.path_parameters)
        url_tpl_params["externalConnection%2Did"] = external_connection_id
        return ExternalConnectionItemRequestBuilder(self.request_adapter, url_tpl_params)

        Provides operations to manage the collection of externalConnection entities.
        param external_connection_id: The unique identifier of externalConnection
        Returns: ExternalConnectionItemRequestBuilder
        
msgraph/generated/connections/connections_request_builder.py