<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def introspection_from_schema( schema: GraphQLSchema, descriptions: bool = True ) -> IntrospectionSchema: """Build an IntrospectionQuery from a GraphQLSchema IntrospectionQuery is useful for utilities that care about type and field relationships, but do not need to traverse through those relationships. This is the inverse of build_client_schema. The primary use case is outside of the server context, for instance when doing schema comparisons. """

    query_ast = parse(get_introspection_query(descriptions))

    from ..execution.execute import execute, ExecutionResult

    result = execute(schema, query_ast)
    if not isinstance(result, ExecutionResult):
        raise RuntimeError("Introspection cannot be executed")
    if result.errors or not result.data:
        raise result.errors[0] if result.errors else GraphQLError(
            "Introspection did not return a result"
        )
    return result.data