def METHOD_NAME(self) -> Mapping[str, Any]:
    """
    Returns the JSON schema.
    The final schema is constructed by first generating a schema for the fields
    in the config and, if default fields should be included, adding these to the
    schema.
    """
    schema = self._get_json_schema_from_config()
    if self.config.get("custom_reports_include_default_fields"):
        default_schema = self._get_json_schema_from_file()
        schema = self._union_schemas(default_schema, schema)
    return schema