@classmethod<EOL><INDENT>def make_string_field_value(cls, field):<DEDENT>
if field.regex is not None:<EOL><INDENT>raise NotImplementedError<EOL><DEDENT>string_range = cls.get_range(field)<EOL>return cls.get_random_string(string_range)<EOL>
String Field has three constraints (apart from anything
in the super class)

Args:
    field (StringField): actual string field object from a
    model declaration

Returns:
    random string value