docs: public static @CheckForNull
      ClassDescriptor createClassDescriptorFromFieldSignature(String signature) {
          int start = signature.indexOf('L');
          if (start < 0) {
              return null;
          }
          int end = signature.indexOf(';', start);
          if (end < 0) {
              return null;
          }
          return createClassDescriptor(signature.substring(start + 1, end));
      }