code: def add_field(self, field, arg=None, value=None, extended=False,
                    hidden=False, e_type=str, required=None):
          
          if required is None:
              required = self._required
          if arg is None:
              arg = re.sub('(?!^)([A-Z]+)', r'_\1', field).lower()
          self._fields[field] = {
              'field': field,
              'arg': arg,
              'value': value,
              'extended': extended,
              'required': required,
              'e_type': e_type,
              'hidden': hidden
          }
docs: Add a new field to the current ResourceBuilder.
  
             Keyword arguments:
             field    -- field name
             arg      -- name of the attribute name in arg object (argparse)
             value    -- a default for this field, used for resource creation.
             extended -- If set to true, the current field will be display in
                         extended list mode only.
             hidden   -- If set to true, the current field won't be exposed
                         as available keys.
             e_type   -- field data type (default str): int, float, str
             required -- True if the current field is required for create
                         and update methods