code: def validate_fields(attributes):
      fields = {
          key: value
          for key, value in attributes.items()
          if isinstance(value, BaseField)
      }
      taken_names = set()
      for name, field in fields.items():
          structue_name = field.structue_name(name)
          if structue_name in taken_names:
              raise ValueError("Name taken", structue_name, name)
          taken_names.add(structue_name)
  
imports: import six
  from .None import parsers, errors
  from .fields import BaseField
  from .errors import ValidationError
label_desc: Use image node_id 2 for calling the JsonmodelMeta obj's underlying member method code with example usage: obj.validate_fields(attributes) without return types