### Question:
RexProgram { public RexProgram normalize(RexBuilder rexBuilder, RexSimplify simplify) { assert isValid(Litmus.THROW, null); final RexProgramBuilder builder = RexProgramBuilder.create(rexBuilder, inputRowType, exprs, projects, condition, outputRowType, true, simplify); return builder.getProgram(false); } RexProgram(
      RelDataType inputRowType,
      List<? extends RexNode> exprs,
      List<RexLocalRef> projects,
      RexLocalRef condition,
      RelDataType outputRowType); List<RexNode> getExprList(); List<RexLocalRef> getProjectList(); List<Pair<RexLocalRef, String>> getNamedProjects(); RexLocalRef getCondition(); static RexProgram create(
      RelDataType inputRowType,
      List<? extends RexNode> projectExprs,
      RexNode conditionExpr,
      RelDataType outputRowType,
      RexBuilder rexBuilder); static RexProgram create(
      RelDataType inputRowType,
      List<? extends RexNode> projectExprs,
      RexNode conditionExpr,
      List<String> fieldNames,
      RexBuilder rexBuilder); static RexProgram create(RelInput input); @Override String toString(); RelWriter explainCalc(RelWriter pw); RelWriter collectExplainTerms(
      String prefix,
      RelWriter pw); RelWriter collectExplainTerms(
      String prefix,
      RelWriter pw,
      SqlExplainLevel level); int getExprCount(); static RexProgram createIdentity(RelDataType rowType); static RexProgram createIdentity(
      RelDataType rowType,
      RelDataType outputRowType); RelDataType getInputRowType(); boolean containsAggs(); RelDataType getOutputRowType(); boolean isValid(Litmus litmus, RelNode.Context context); boolean isNull(RexNode expr); RexNode expandLocalRef(RexLocalRef ref); Pair<ImmutableList<RexNode>, ImmutableList<RexNode>> split(); List<RelCollation> getCollations(List<RelCollation> inputCollations); static void deduceCollations(
      List<RelCollation> outputCollations,
      final int sourceCount,
      List<RexLocalRef> refs,
      List<RelCollation> inputCollations); boolean projectsIdentity(final boolean fail); boolean projectsOnlyIdentity(); boolean isTrivial(); int[] getReferenceCounts(); boolean isConstant(RexNode ref); RexNode gatherExpr(RexNode expr); int getSourceField(int outputOrdinal); boolean isPermutation(); Permutation getPermutation(); Set<String> getCorrelVariableNames(); boolean isNormalized(Litmus litmus, RexBuilder rexBuilder); RexProgram normalize(RexBuilder rexBuilder, RexSimplify simplify); @Deprecated // to be removed before 2.0 RexProgram normalize(RexBuilder rexBuilder, boolean simplify); Mappings.TargetMapping getPartialMapping(int inputFieldCount);  }### Answer:
@Test void testNormalize() { final RexProgramBuilder builder = createProg(0); final String program = builder.getProgram(true).toString(); TestUtil.assertEqualsVerbose( "(expr#0..1=[{inputs}], expr#2=[+($t0, $t1)], expr#3=[1], " + "expr#4=[+($t0, $t3)], expr#5=[+($t2, $t4)], " + "expr#6=[+($t0, $t0)], a=[$t5], b=[$t6])", program); }