How to use the relay-compiler.IRTransforms.schemaExtensions function in relay-compiler

function generate(
  text: string,
  schema: GraphQLSchema,
  transforms: RelayCompilerTransforms,
): {[key: string]: GeneratedNode} {
  const {
    compileRelayArtifacts,
    GraphQLCompilerContext,
    IRTransforms,
    transformASTSchema,
  } = require('relay-compiler');

  const relaySchema = transformASTSchema(schema, IRTransforms.schemaExtensions);
  const compilerContext = new GraphQLCompilerContext(
    schema,
    relaySchema,
  ).addAll(parseGraphQLText(relaySchema, text).definitions);
  const documentMap = {};
  compileRelayArtifacts(compilerContext, transforms).forEach(
    ([_definition, node]) => {
      documentMap[
        node.kind === 'Request' ? node.params.name : node.name
      ] = node;
    },
  );
  return documentMap;
}

function generate(
  text: string,
  schema: GraphQLSchema,
  transforms: RelayCompilerTransforms,
  moduleMap: ?{[string]: mixed},
): {[key: string]: GeneratedNode} {
  const relaySchema = transformASTSchema(schema, IRTransforms.schemaExtensions);
  const {definitions, schema: extendedSchema} = parseGraphQLText(
    relaySchema,
    text,
  );
  const compilerContext = new GraphQLCompilerContext(
    Schema.DEPRECATED__create(schema, extendedSchema),
  ).addAll(definitions);
  const documentMap = {};
  compileRelayArtifacts(compilerContext, transforms).forEach(
    ([_definition, node]) => {
      const transformedNode =
        moduleMap != null ? CodeMarker.transform(node, moduleMap) : node;
      documentMap[
        node.kind === 'Request' ? node.params.name : node.name
      ] = transformedNode;
    },