framework/db/SqlToken.php
public function offsetUnset($offset)
    {
        $offset = $this->calculateOffset($offset);
        if (isset($this->_children[$offset])) {
            array_splice($this->_children, $offset, 1);
        }
        $this->updateCollectionOffsets();
    }
public function offsetUnset($offset)
    {
        $offset = $this->calculateOffset($offset);
        if (isset($this->_children[$offset])) {
            array_splice($this->_children, $offset, 1);
        }
        $this->updateCollectionOffsets();
    }
Removes a child token at the specified offset.
This method is required by the SPL [[\ArrayAccess]] interface.
It is implicitly called when you use something like `unset($token[$offset])`.
@param int $offset child token offset.