code: @Override
      public boolean matches(IAtom atom) {
          return Preconditions.checkNotNull(atom.getAtomicNumber(), "Atomic number is not set.").equals(
                  this.getAtomicNumber());
      }
docs: /*
  (non-Javadoc)
  @see
  org.openscience.cdk.isomorphism.matchers.smarts.SMARTSAtom#matches(org
  .openscience.cdk.interfaces.IAtom)