code: public function combine(array $keys): self
  	{
  		if (count($keys) !== count($this->_container)) {
  			throw new LengthException('array counts do not match');
  		}
  
  		$this->_container = array_combine($keys, $this->_container);
  
  		return $this;
  	}
docs: Apply new names from input array values.
  
  @param array $keys
  
  @return TypedArray
  @throws LengthException