code: function useSchema(
    definition: SchemaDefinition,
    schema: GraphQLSchema,
    prefix?: ?string
  ) {
    const factoryDef = deconstructSchema(schema, prefix);
    return definition.merge(factoryDef);
  }
docs: Adds a schema to the definition
  @param {*} definition
  @param {*} schema
  @param {*} prefix