code: public DepictionGenerator withAtomMapNumbers() {
          if (annotateAtomNum)
              throw new IllegalArgumentException("Can not annotated atom maps, atom numbers or values are already annotated");
          DepictionGenerator copy = new DepictionGenerator(this);
          copy.annotateAtomMap = true;
          return copy;
      }
docs: Display atom-atom mapping numbers on a reaction. Each atom map index
  is loaded from the property {@link CDKConstants#ATOM_ATOM_MAPPING}.
  
  Note: A depiction can not have both atom numbers and atom
  maps visible (but this can be achieved by manually setting
  the annotation).
  
  @return new generator for method chaining
  @see #withAtomNumbers()
  @see CDKConstants#ATOM_ATOM_MAPPING
  @see StandardGenerator#ANNOTATION_LABEL