public String getErrorDisplay(String s) {
		StringBuilder buf = new StringBuilder();
		for (char c : s.toCharArray()) {
			buf.append(getErrorDisplay(c));
		}
		return buf.toString();
	}
Return a list of all Token objects in input char stream.
 Forces load of all tokens. Does not include EOF token.
runtime/Java/src/org/antlr/v4/runtime/Lexer.java