GridFieldOrderableRows::setSortField PHP Method

    public function setSortField($field)
    {
        $this->sortField = $field;
        return $this;
    }

 /**
  * @covers GridFieldOrderableRows::getSortTable
  */
 public function testGetSortTable()
 {
     $orderable = new GridFieldOrderableRows();
     $parent = new GridFieldOrderableRowsTest_Parent();
     $parent->write();
     $this->assertEquals('GridFieldOrderableRowsTest_Ordered', $orderable->getSortTable($parent->HasMany()));
     $this->assertEquals('GridFieldOrderableRowsTest_Ordered', $orderable->getSortTable($parent->HasManySubclass()));
     $this->assertEquals('GridFieldOrderableRowsTest_Ordered', $orderable->getSortTable($parent->ManyMany()));
     $this->assertEquals('GridFieldOrderableRowsTest_Parent_ManyMany', $orderable->setSortField('ManyManySort')->getSortTable($parent->ManyMany()));
 }