message: Save injector immediately after it's created
diff: @@ -364,6 +364,8 @@ export class GraphQLModule<Config = any, Request = any, Context = any> {
  injector.init(provider);
  }
  + this._cache.injector = injector;
  +
  const resolvers = this.selfResolvers;
  // tslint:disable-next-line:forin
  for ( const type in resolvers ) {
  @@ -447,8 +449,6 @@ export class GraphQLModule<Config = any, Request = any, Context = any> {
  }
  }
  - this._cache.injector = injector;
  -
  this._cache.contextBuilder = async networkRequest => {
  const importsContextArr$ = [...importsContextBuilders].map(contextBuilder => contextBuilder(networkRequest));
  const importsContextArr = await Promise.all(importsContextArr$);
  