@Nullable
	private String map(@Nullable String signature, @Nonnull Types.SignatureContext type) {
		if (Types.isValidSignature(signature, type))
			return signature;
		detected = true;
		return null;
	}
@return {@code true} if any illegal signatures were removed.
recaf-core/src/main/java/software/coley/recaf/util/visitors/IllegalSignatureRemovingVisitor.java