code: public String readAttributeAsFixedLengthString(String attributeName, int bufferSize)
              throws UnsupportedKerasConfigurationException {
          synchronized (Hdf5Archive.LOCK_OBJECT) {
              Attribute a = this.file.openAttribute(attributeName);
              String s = readAttributeAsFixedLengthString(a, bufferSize);
              a.deallocate();
              return s;
          }
      }
docs: Read string attribute from group path.
  
  @param attributeName Name of attribute
  @param bufferSize    buffer size to read
  @return Fixed-length string read from HDF5 attribute name
  @throws UnsupportedKerasConfigurationException Unsupported Keras config