code: public function draw($workflow)
  	{
  		$this->geometry->setCore($workflow);
  
  		$this->setPipesOfWorkflow($workflow);
  
  		$this->drawCenteredChar(static::NOCK);
  
  		$this->drawPipesBeginning();
  
  		$this->drawCore();
  
  		$this->drawPipesEnd();
  
  		$this->drawCenteredChar(static::PILE);
  
  		return $this->drawing;
  	}
docs: Draw the given workflow.
  
  @author	Andrea Marco Sartori
  @param	string	$workflow
  @return	string