code: public CMAEntry update(CMAEntry entry) {
      assertNotNull(entry, "entry");
      final String entryId = getResourceIdOrThrow(entry, "entry");
      final String spaceId = getSpaceIdOrThrow(entry, "entry");
      final String environmentId = entry.getEnvironmentId();
      final Integer version = getVersionOrThrow(entry, "update");
  
      final CMASystem system = entry.getSystem();
      entry.setSystem(null);
      try {
        return service.update(version, spaceId, environmentId, entryId, entry).blockingFirst();
      } finally {
        entry.setSystem(system);
      }
    }
docs: Update an Entry.
  
  @param entry Entry
  @return {@link CMAEntry} result instance
  @throws IllegalArgumentException if entry is null.
  @throws IllegalArgumentException if entry's id is null.
  @throws IllegalArgumentException if entry's space id is null.
  @throws IllegalArgumentException if entry's version is null.