code: private NameAndVersion splitRequestedNameAndVersion(String nameAndVersion) {
          String[] parts = nameAndVersion.split("/");
          if (parts.length > 2) {
              throw new IllegalArgumentException("Only one \"/\" symbol is allowed in the resourceString but it was " + nameAndVersion);
          }
  
          if (parts.length == 2) {
              return new NameAndVersion(parts[0], parts[1]);
          } else {
              return new NameAndVersion(nameAndVersion, null);
          }
      }
docs: Users can request a specific version to be installed using the format {@code myFeature/1.2.0}.
  <p>
  This method splits the string around the first slash character and returns the results.
  
  @param nameAndVersion the feature name, as passed into {@link #resolve(Collection)}
  @return the split name and version. The version component may be null.