code: public void addLiteral(final INodeReadTrx pTrans, final AtomicValue pVal) {
          getExpression().add(new LiteralExpr(pTrans, AbsAxis.addAtomicToItemList(pTrans, pVal)));
      }
docs: Adds a literal expression to the pipeline.
  
  @param pTrans
  Transaction to operate with.
  @param pVal
  key of the literal expression.