query method
Executes a GraphQL query and returns a promise with the result.
Implementation
Future<Map<String, dynamic>?> query(
{required String operationName,
required String query,
Map<String, dynamic> variables = const {}}) =>
_client
.query(graphql.QueryOptions(
document: graphql.gql(query),
variables: variables,
operationName: operationName))
.then((value) => value.data);