private boolean isAscii() {
		for (byte b : _typeBytes) {
			if (b < ' ' || b > 126) {
				return false;
			}
		}
		return true;
	}
Returns the offset from the beginning of the 
resource type list to reference list for this type.
@return the offset to reference list
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/macos/rm/ResourceType.java