title: Method does not exist or incorrect signature
body: <p>I am trying to implement a simple change for an apex class in production. I have the proper class and proper test class. The test class runs successfully in sandbox without errors, but apparently the error is coming from the TestHelper default test class in Salesforce. When trying to deploy in production it throws the error "Method does not exist or incorrect signature: void createUser(Id, String, String, Date, Integer) from the type TestHelper"</p>
  
  <p>I've tried the usual of changing the method it references to public static void, but to no avail, it throws errors in code</p>
  
  <p>This is my test class:</p>
  
  <pre><code>@isTest
  private class OppLineItemInvntryBO_AType_OppStge_Test {   
  
      @testSetup public static void setup() {
          Profile p = [SELECT Id FROM Profile 
              WHERE Name = 'profile1' LIMIT 1];
  
              Date myDate = Date.newinstance(2019,07,01);
  
          User testUser = TestHelper.createUser(p.Id, 
                 'company1','legalentity1',myDate,327001);
  
  </code></pre>
  
  <p>And this is my TestHelper class:</p>
  
  <pre><code>public with sharing class TestHelper {
    public static User createUser(Id profileId, String company) {
      Integer rnd = getRandomNumber(10000);
  
      User user = new User(
        Username = 'john.doe@acme.com' + String.valueOf(rnd),
        Email = 'john.doe' + String.valueOf(rnd) + '@acme.com',
        LastName = 'Doe',
        FirstName = 'John',
        Alias = 'JD' + String.valueOf(rnd),
        ProfileId = profileId,
        LocaleSidKey = 'en_US',
              LanguageLocaleKey = 'en_US',
              TimeZoneSidKey = 'America/Los_Angeles',
              EmailEncodingKey='UTF-8',
              CompanyName = company);
      insert user;
      return user;
    }
  
    public static Integer getRandomNumber(Integer size){
      Double d = math.random() * size;
      return d.intValue();
    }
  }
  
  
  </code></pre>
  
  <p>The full error is this:</p>
  
  <p>API Name - OppLineItemInvntryBO_AType_OppStge_Test
  Type - Apex Class
  Line - 14
  Column - 36
  Error Message - Method does not exist or incorrect signature: void createUser(Id, String, String, Date, Integer) from the type TestHelper</p>