kind
kind:
| "CStyleCastExpr"
| "ImplicitCastExpr"
| "ArraySubscriptExpr"
| "CallExpr"
| "CharacterLiteral"
| "CompoundLiteralExpr"
| "ConditionalOperator"
| "ConstantExpr"
| "FloatingLiteral"
| "ImplicitValueInitExpr"
| "InitListExpr"
| "IntegerLiteral"
| "ParenExpr"
| "PredefinedExpr"
| "StmtExpr"
| "StringLiteral"
| "UnaryExprOrTypeTraitExpr"
Hexadecimal ID for the node, e.g. "0x..."