@Test
  public void testUnaryMinusColumnDouble() throws HiveException {
    ExprNodeColumnDesc col1Expr = new  ExprNodeColumnDesc(Float.class, "col1", "table", false);
    GenericUDF gudf = new GenericUDFOPNegative();
    List<ExprNodeDesc> children = new ArrayList<ExprNodeDesc>(1);
    children.add(col1Expr);
    ExprNodeGenericFuncDesc negExprDesc = new ExprNodeGenericFuncDesc(TypeInfoFactory.doubleTypeInfo, gudf,
        children);
    List<String> columns = new ArrayList<String>();
    columns.add("col0");
    columns.add("col1");
    VectorizationContext vc = new VectorizationContext("name", columns);

    VectorExpression ve = vc.getVectorExpression(negExprDesc, VectorExpressionDescriptor.Mode.PROJECTION);

    assertTrue( ve instanceof DoubleColUnaryMinus);
  }
Create original expression tree for following
(plus (minus (plus col1 col2) col3) (multiply col4 (mod col5 col6)) )
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/TestVectorizationContext.java