/**
* Function: setCellStyles
*
* Sets the key to value in the styles of the given cells. This will modify
* the existing cell styles in-place and override any existing assignment
* for the given key. If no cells are specified, then the selection cells
* are changed. If no value is specified, then the respective key is
* removed from the styles.
*
* Parameters:
*
* key - String representing the key to be assigned.
* value - String representing the new value for the key.
* cells - Array of <mxCells> to change the style for.
*/
function setCellStyles($key, $value, $cells)
{
mxUtils::setCellStyles($this->model, $cells, $key, $value);
}