docs: @CheckForNull
      private DetailAST getExprAst(@Nonnull final DetailAST pAst)
      {
          DetailAST result = null;
          for (DetailAST a = pAst.getFirstChild(); a != null; a = a.getNextSibling()) {
              if (a.getType() != TokenTypes.LPAREN && a.getType() != TokenTypes.RPAREN) {
                  result = a;
                  break;
              }
          }
          return result;
      }