final public function setEnhanceSigchildCompatibility($enhance)
    {
        if ($this->isRunning()) {
            throw new \RuntimeException('Process is already running');
        }

        $this->enhanceSigchildCompatibility = (bool) $enhance;

        return $this;
    }
final public function setEnhanceSigchildCompatibility($enhance)
    {
        if ($this->isRunning()) {
            throw new \RuntimeException('Process is already running');
        }

        $this->enhanceSigchildCompatibility = (bool) $enhance;

        return $this;
    }
final public function setEnhanceSigchildCompatibility ( $ enhance ) { if ( $ this -> isRunning ( ) ) { throw new \ RuntimeException ( 'Process is already running' ) ; } $ this -> enhanceSigchildCompatibility = ( bool ) $ enhance ; return $ this ; }
Enable or disable sigchild compatibility mode.

Sigchild compatibility mode is required to get the exit code and
determine the success of a process when PHP has been compiled with
the --enable-sigchild option.

@param bool $enhance

@throws RuntimeException If the process is already running

@return self
Enable or disable sigchild compatibility mode .