code: public boolean removeObjective(Objective<? super SolutionType, ? super DataType> objective){
          if(weights.containsKey(objective)){
              weights.remove(objective);
              return true;
          } else {
              return false;
          }
      }
docs: Remove an objective, if present. Returns <code>true</code> if the objective has been successfully
  removed, <code>false</code> if it was not contained in the index.
  
  @param objective objective to remove
  @return <code>true</code> if the objective has been successfully removed