code: public ManagementGate getInputGate(final int index) {
  
  		if (index < this.inputGates.size()) {
  			return this.inputGates.get(index);
  		}
  
  		return null;
  	}
docs: Returns the input gate at the given index.
  
  @param index
  the index of the input gate to be returned
  @return the input gate at the given index or <code>null</code> if no such input gate exists