Meteorjs test Meteor methods

I have the following simple Meteor Method that I want to test. It inserts a given Object into my collection

Meteor.methods({
  insertHelper(profile){
      HelperCollection.insert(profile);
      return true;
   },
}

For Testing i use "dispatch:mocha-phantomjs" My Test so far is the following:

describe('methods', () => {
  it('can delete owned task', () => {
    Meteor.call('insertHelper',{a: 1});
  });
});

When running my tests I get the message " Error: Method 'insertHelper' not found [404]"

So how can I access my Meteor methods from my Test suite?