code: @Override
      public DescriptorValue calculate(IAtom first, IAtom second, IAtomContainer atomContainer) {
          IAtomContainer ac;
          try {
              ac = (IAtomContainer) atomContainer.clone();
          } catch (CloneNotSupportedException e) {
              return getDummyDescriptorValue(e);
          }
          IAtom clonedFirst = ac.getAtom(atomContainer.indexOf(first));
          IAtom clonedSecond = ac.getAtom(atomContainer.indexOf(first));
  
          IAtomContainer mol = ac.getBuilder().newInstance(IAtomContainer.class, ac);
          if (checkAromaticity) {
              try {
                  AtomContainerManipulator.percieveAtomTypesAndConfigureAtoms(mol);
                  Aromaticity.cdkLegacy().apply(mol);
              } catch (CDKException e) {
                  return getDummyDescriptorValue(e);
              }
          }
          boolean piContact = false;
          int counter = 0;
  
          if (acold != ac) {
              acold = ac;
              acSet = ConjugatedPiSystemsDetector.detect(mol);
          }
          java.util.Iterator<IAtomContainer> detected = acSet.atomContainers().iterator();
  
          List<IAtom> neighboorsFirst = mol.getConnectedAtomsList(clonedFirst);
          List<IAtom> neighboorsSecond = mol.getConnectedAtomsList(clonedSecond);
  
          while (detected.hasNext()) {
              IAtomContainer detectedAC = detected.next();
              if (detectedAC.contains(clonedFirst) && detectedAC.contains(clonedSecond)) {
                  counter += 1;
                  break;
              }
              if (isANeighboorsInAnAtomContainer(neighboorsFirst, detectedAC)
                      && isANeighboorsInAnAtomContainer(neighboorsSecond, detectedAC)) {
                  counter += 1;
                  break;
              }
          }
  
          if (counter > 0) {
              piContact = true;
          }
          return new DescriptorValue(getSpecification(), getParameterNames(), getParameters(), new BooleanResult(
                  piContact), getDescriptorNames());
      }
docs: The method returns if two atoms have pi-contact.
  
  @param  atomContainer                AtomContainer
  @return                   true if the atoms have pi-contact