code: IAtom newCDKAtom(Atom atom) {
          Element element = atom.element();
          boolean unknown = element == Element.Unknown;
          if (unknown) {
              IPseudoAtom pseudoAtom = builder.newInstance(IPseudoAtom.class, element.symbol());
              pseudoAtom.setSymbol(element.symbol());
              pseudoAtom.setLabel(atom.label());
              return pseudoAtom;
          }
          return createAtom(element);
      }
docs: Create a new CDK {@link IAtom} from the Beam Atom. If the element is
  unknown (i.e. '*') then an pseudo atom is created.
  
  @param atom an Atom from the Beam Graph
  @return the CDK atom to have it's properties set