docs: static void checkMethodIdentifier(int version, final String name,
              final String msg) {
          if (name == null || name.length() == 0) {
              throw new IllegalArgumentException("Invalid " + msg
                      + " (must not be null or empty)");
          }
          if ((version & 0xFFFF) >= Opcodes.V1_5) {
              for (int i = 0; i < name.length(); ++i) {
                  if (".;[/<>".indexOf(name.charAt(i)) != -1) {
                      throw new IllegalArgumentException("Invalid " + msg
                              + " (must be a valid unqualified name): " + name);
                  }
              }
              return;
          }
          if (!Character.isJavaIdentifierStart(name.charAt(0))) {
              throw new IllegalArgumentException(
                      "Invalid "
                              + msg
                              + " (must be a '<init>', '<clinit>' or a valid Java identifier): "
                              + name);
          }
          for (int i = 1; i < name.length(); ++i) {
              if (!Character.isJavaIdentifierPart(name.charAt(i))) {
                  throw new IllegalArgumentException(
                          "Invalid "
                                  + msg
                                  + " (must be '<init>' or '<clinit>' or a valid Java identifier): "
                                  + name);
              }
          }
      }