ImageToolkitBase::setSource

public ImageToolkitBase::setSource($source)

public function setSource($source) {
  // If a previous image has been loaded, there is no way to know if the
  // toolkit implementation needs to perform any additional actions like
  // freeing memory. Therefore, the source image cannot be changed once set.
  if ($this->source) {
    throw new \BadMethodCallException(__METHOD__ . '() may only be called once');
  }
  $this->source = $source;
  return $this;
}