code: public EnvironmentConfig setTreeDupMaxPageSize(final int pageSize) throws InvalidSettingException {
          if (pageSize < 8 || pageSize > 128) {
              throw new InvalidSettingException("Invalid dup tree page size: " + pageSize);
          }
          return setSetting(TREE_DUP_MAX_PAGE_SIZE, pageSize);
      }
docs: Sets the maximum size of page of duplicates sub-B+Tree. Default value is {@code 8}. Only sizes in the range [8..128]
  are accepted.
  <p>Mutable at runtime: yes
  
  @param pageSize maximum size of page of duplicates sub-B+Tree
  @return this {@code EnvironmentConfig} instance
  @throws InvalidSettingException page size is not in the range [8..128]