SearchBuilderOptions()/SearchPaneOptions() include unrelated Left Joins

In the samples SearchBuilderController.cs adding addition joins show up in that search builder query:

      .Field(new Field("users.site")
          .Options(new Options()
              .Table("sites")
              .Value("id")
              .Label("name")
          )
      )
      .Field(new Field("sites.name")
          .SearchBuilderOptions(new SearchBuilderOptions()
              .Label("sites.name")
              .Value("sites.name")
              .LeftJoin("sites", "sites.id", "=", "users.site")
          )
      )
    .LeftJoin("sites", "sites.id", "=", "users.site")
    .LeftJoin("user_dept", "users.id", "=", "user_dept.user_id")

SELECT  sites.name as 'value', sites.name as 'label' 
FROM  users 
LEFT JOIN sites ON sites.id = users.site  
LEFT JOIN user_dept ON users.id = user_dept.user_id  
GROUP BY sites.name

Start with the SearchBuilderController.cs sample and trace how SearchBuilderOptions() and SearchPaneOptions() generate their queries and inherit joins. Compare the generated SQL with the joins declared for the field and the parent query. Done means unrelated LEFT JOIN clauses no longer appear in the search builder query.