How to use the apollo-utilities.getMainDefinition function in apollo-utilities

const link = split(({query}) => {
      const { kind, operation } = getMainDefinition(query);
      return kind === 'OperationDefinition' && operation == 'subscription';
    }, wsLink, authLink.concat(httpLink));

({ query }) => {
        const { kind, operation } = getMainDefinition(
          query
        ) as OperationDefinitionNode;
        return kind === 'OperationDefinition' && operation === 'subscription';
      },
      wsLink,

({ query }) => {
    const { kind, operation } = getMainDefinition(query);
    return kind === 'OperationDefinition' && operation === 'subscription';
  },
  wsLink,

({ query }) => {
    const { kind, operation } = getMainDefinition(query);
    return kind === 'OperationDefinition' && operation === 'subscription';
  },
  wsLink,

({ query }) => {
    const { kind, operation } = getMainDefinition(query);
    return kind === 'OperationDefinition' && operation === 'subscription';
  },
  wsLink,

({ query }) => {
    const { kind, operation }: any = getMainDefinition(query);
    return kind === "OperationDefinition" && operation === "subscription";
  },
  wsLink,

const updateBaseWithDelta = (
    logger,
    baseQuery: BuildBaseQuerySyncOptions,
    otherQuery: BuildQuerySyncOptions,
    cache: DataProxy,
    data: T,
    cacheUpdates: (item: T) => QueryWithVariables[] = () => [] as QueryWithVariables[],
    typename: string,
    idField: string = 'id',
) => {
    const updateLogger = logger.extend('update');

    const opDefinition = getMainDefinition(otherQuery.query);
    const { name: { value: opName }, alias: opAliasNode } = opDefinition.selectionSet.selections[0] as FieldNode;
    const { value: opAlias = null } = opAliasNode || {};

    const { kind, operation: graphqlOperation } = opDefinition as OperationDefinitionNode;
    const isSubscription = kind === 'OperationDefinition' && graphqlOperation === 'subscription';

    const [deltaOperationName] = isSubscription ? Object.keys(data) : [opAlias || opName];
    const { [deltaOperationName]: records }: { [key: string]: any } = data;
    const deltaRecords = [].concat(records) as T[];

    if (!baseQuery || !baseQuery.query) {
        updateLogger('No baseQuery provided');
    } else {
        const { query, variables } = baseQuery;

        const operationName = getOperationFieldName(query);

({ query }) => {
    const { kind, operation } = getMainDefinition(query);
    return kind === 'OperationDefinition' && operation === 'subscription';
  },
  wsLink,

({ query }) => {
            const { kind, operation } = getMainDefinition(query)
            return kind === 'OperationDefinition' &&
              operation === 'subscription'
          },
          wsLink,

({ query }) => {
        const { kind, operation } = getMainDefinition(query)
        return kind === 'OperationDefinition' && operation === 'subscription'
      },
      ws,