original_string: public function unregister($alias, $remove_instances=false)
  	{
  		$alias = strtolower($alias);
  
  		if ($remove_instances && array_key_exists($alias, $this->instances))
  		{
  			$this->instances[$alias] = null;
  			unset($this->instances[$alias]);
  		}
  
  		unset($this->services[$alias]);
  
  		return $this;
  	}
code: public function unregister($alias, $remove_instances=false)
  	{
  		$alias = strtolower($alias);
  
  		if ($remove_instances && array_key_exists($alias, $this->instances))
  		{
  			$this->instances[$alias] = null;
  			unset($this->instances[$alias]);
  		}
  
  		unset($this->services[$alias]);
  
  		return $this;
  	}
code_tokens: public function unregister ( $ alias , $ remove_instances = false ) { $ alias = strtolower ( $ alias ) ; if ( $ remove_instances && array_key_exists ( $ alias , $ this -> instances ) ) { $ this -> instances [ $ alias ] = null ; unset ( $ this -> instances [ $ alias ] ) ; } unset ( $ this -> services [ $ alias ] ) ; return $ this ; }
docstring: Unregisters a single service provider. If an instance of that
  provider has already been created, it will be destroyed.
  
  @param $alias
  
  @return $this
docstring_tokens: Unregisters a single service provider . If an instance of that provider has already been created it will be destroyed .