code: public T modifyModule(final String moduleName, final String slot, final byte[] existingHash, final byte[] newHash) {
          final ContentItem item = createModuleItem(moduleName, slot, newHash);
          addContentModification(createContentModification(item, ModificationType.MODIFY, existingHash));
          return returnThis();
      }
docs: Modify a module.
  
  @param moduleName the module name
  @param slot the module slot
  @param existingHash the existing hash
  @param newHash the new hash of the modified content
  @return the builder