private boolean hasVarArgs(String newSignatureText) {
		int startIndex = newSignatureText.lastIndexOf(',');
		int endIndex = newSignatureText.indexOf(')');
		if (startIndex < 0 || endIndex < 0 || startIndex >= endIndex) {
			return false;
		}
		String lastArg = newSignatureText.substring(startIndex + 1, endIndex).trim();
		return "...".equals(lastArg);
	}
Parse the given function signature text into a FunctionDefinitionDataType.

@param originalSignature the function signature before editing. This may be
                         null if the user is entering a new signature instead
                         of editing an existing one.
@param signatureText     the text to be parsed into a function signature.
@return the FunctionDefinitionDataType resulting from parsing.
@throws ParseException if the text could not be parsed.
@throws CancelledException if parse cancelled by user
Ghidra/Features/Base/src/main/java/ghidra/app/util/parser/FunctionSignatureParser.java