protected List<List<Statement>> buildContext(
      InputContext inputContext, List<Statement> stmts, int targetIndex) {
    VarCartesianProduct varCartesianProduct = new VarCartesianProduct();
    Statement statement = stmts.get(targetIndex);

    for (CtVariableReference var : statement.getInputContext().getVar()) {

      varCartesianProduct.addReplaceVar(var, valueCreator.createNull(var.getType()));

      List<CtVariableReference> candidates = inputContext.allCandidate(var.getType(), true, false);
      if (!candidates.isEmpty()) {
        varCartesianProduct.addReplaceVar(
            var, candidates.get(AmplificationHelper.getRandom().nextInt(candidates.size())));
      }

      Statement cfLocalVar = getLocalVar(var.getType(), inputContext);
      if (cfLocalVar != null) {
        varCartesianProduct.addReplaceVar(var, cfLocalVar);
      }

      CtLocalVariable localVariable =
          createLocalVarFromMethodLiterals(currentMethod, var.getType());
      if (localVariable != null) {
        varCartesianProduct.addReplaceVar(var, localVariable);
      }

      CtLocalVariable randomVar = valueCreator.createRandomLocalVar(var.getType());
      if (randomVar != null) {
        varCartesianProduct.addReplaceVar(var, randomVar);
      }
    }

    return varCartesianProduct.apply(stmts, targetIndex);
  }
  protected boolean isValidCodeFragment(Statement cf) {
    CtCodeElement codeElement = cf.getCtCodeFragment();

    if (CtLocalVariable.class.isInstance(codeElement)) {
      Object defaultExpression = ((CtLocalVariable) codeElement).getDefaultExpression();
      return defaultExpression != null;
    }
    return false;
  }
  protected Statement getLocalVar(CtTypeReference type, InputContext inputContext) {
    List<Statement> list =
        localVars
            .stream()
            .filter(var -> var.getCtCodeFragment() != null)
            .filter(var -> type.equals(((CtLocalVariable) var.getCtCodeFragment()).getType()))
            .filter(
                var ->
                    inputContext.getVariableOrFieldNamed(
                            ((CtLocalVariable) var.getCtCodeFragment()).getSimpleName())
                        == null)
            .collect(Collectors.toList());

    if (list.isEmpty()) {
      return null;
    } else {
      boolean localVarFind;
      while (!list.isEmpty()) {
        Statement localVar = list.remove(AmplificationHelper.getRandom().nextInt(list.size()));
        localVarFind = true;
        for (CtVariableReference var : localVar.getInputContext().getVar()) {
          CtVariableReference<?> candidate = inputContext.candidate(var.getType(), true);
          if (candidate == null) {
            localVarFind = false;
            break;
          }
        }
        if (localVarFind) {
          Statement cloneLocalVar = localVar.clone();
          for (CtVariableReference var : localVar.getInputContext().getVar()) {
            try {
              CtVariableReference variable =
                  cloneLocalVar.getInputContext().getVariableOrFieldNamed(var.getSimpleName());
              cloneLocalVar
                  .getInputContext()
                  .getVariableOrFieldNamed(var.getSimpleName())
                  .replace(variable);
            } catch (Exception e) {
              continue;
            }
            return cloneLocalVar;
          }
        }
      }
      return null;
    }
  }