code: public void addRequirement(Requirement requirement) throws GreenPepperServerException
      {
          if(requirements.contains(requirement) || requirementNameExists(requirement.getName()))
              throw new GreenPepperServerException( GreenPepperServerErrorKey.REQUIREMENT_ALREADY_EXISTS, "Requirement already exists");
  
          requirement.setRepository(this);
          requirements.add(requirement);
      }
docs: <p>addRequirement.</p>
  
  @param requirement a {@link com.greenpepper.server.domain.Requirement} object.
  @throws com.greenpepper.server.GreenPepperServerException if any.