code: def validate_extra_context(ctx, param, value):
      
      for s in value:
          if '=' not in s:
              raise click.BadParameter(
                  'EXTRA_CONTEXT should contain items of the form key=value; '
                  "'{}' doesn't match that form".format(s)
              )
  
      # Convert tuple -- e.g.: (u'program_name=foobar', u'startsecs=66')
      # to dict -- e.g.: {'program_name': 'foobar', 'startsecs': '66'}
      return collections.OrderedDict(s.split('=', 1) for s in value) or None
docs: Validate extra context.