class_docstr: Checker used for string fields.
  
  Always returns a unicode value, even if the input is of type str.
code: def DefaultValue(self):
      return ""
  
imports: import numbers
  import six
  from google.protobuf.internal import api_implementation
  from google.protobuf.internal import decoder
  from google.protobuf.internal import encoder
  from google.protobuf.internal import wire_format
  from google.protobuf import descriptor
label_desc: Use image node_id 2 for calling the UnicodeValueChecker obj's underlying member method code with example usage: obj.DefaultValue() and returns: str