code: def generate_imports_for_referenced_namespaces(
          backend, namespace, insert_type_ignore=False):
      # type: (Backend, ApiNamespace, bool) -> None
      
  
      imported_namespaces = namespace.get_imported_namespaces(consider_annotation_types=True)
      if not imported_namespaces:
          return
  
      type_ignore_comment = TYPE_IGNORE_COMMENT if insert_type_ignore else ""
  
      backend.emit('try:')
      with backend.indent():
          backend.emit('from . import (')
          with backend.indent():
              for ns in imported_namespaces:
                  backend.emit(fmt_namespace(ns.name) + ',')
          backend.emit(')')
      backend.emit('except (ImportError, SystemError, ValueError):')
      # Fallback if imported from outside a package.
      with backend.indent():
          for ns in imported_namespaces:
              backend.emit('import {namespace_name}{type_ignore_comment}'.format(
                  namespace_name=fmt_namespace(ns.name),
                  type_ignore_comment=type_ignore_comment
              ))
      backend.emit()
docs: Both the true Python backend and the Python PEP 484 Type Stub backend have
      to perform the same imports.
  
      :param insert_type_ignore: add a MyPy type-ignore comment to the imports in
          the except: clause.