Tree#toString shouldn't be used for Trees deriving from the code being compiled, as it discards whitespace and comments.

• If this code is within an Error Prone check, using VisitorState#getSourceForNode will give you the original source text. Note that for synthetic trees (e.g.: implicit constructors), that source may be null.

• Prefer Elements#getConstantExpression to TreeMaker.Literal for escaping constants in generated code.