code: def validate_string_dict(dct):
      """Validate that the input is a dict with string keys and values.
  
      Raises ValueError if not."""
      for k, v in iteritems(dct):
          if not isinstance(k, string_types):
              raise ValueError("key %r in dict must be a string" % k)
          if not isinstance(v, string_types):
              raise ValueError("value %r in dict must be a string" % v)
  
imports: from __future__ import absolute_import
  from jupyter_client.channels import major_protocol_version
  from ipython_genutils.py3compat import string_types, iteritems
  import zmq
  from traitlets import Any, Instance, Type
  from .channelsabc import ChannelABC, HBChannelABC
  from .clientabc import KernelClientABC
  from .connect import ConnectionFileMixin
label_desc: Use image node_id 1 for calling a global function with example usage: validate_string_dict(dct) without return types