private Expression parseInExpression(ExpressionContext context, boolean canUseFullPath) {
    Expression childExpression = parseExpression(context.unaryBeforeInExpression, canUseFullPath);
    LinkedHashSet<String> values = new LinkedHashSet<>();
    for (ConstantContext constantContext : context.constant()) {
      values.add(parseConstant(constantContext));
    }
    return new InExpression(childExpression, context.operator_not() != null, values);
  }
function for parsing file path used by LOAD statement.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/parser/ASTVisitor.java