message: Add fields getter to Variant
diff: @@ -2,7 +2,7 @@ import { inspect } from 'util';
  import { GraphQLObjectType } from 'graphql';
  -import { SelectionSet, Selection, FragmentSpread } from '../';
  +import { SelectionSet, Selection, Field, FragmentSpread } from '../';
  import { collectAndMergeFields } from './collectAndMergeFields';
  export class Variant implements SelectionSet {
  @@ -12,6 +12,10 @@ export class Variant implements SelectionSet {
  public fragmentSpreads: FragmentSpread[] = []
  ) {}
  + get fields(): Field[] {
  + return collectAndMergeFields(this);
  + }
  +
  inspect() {
  return `${inspect(this.possibleTypes)} -> ${inspect(
  collectAndMergeFields(this, false).map(field => field.responseKey)
  