def init(cls, typ, class2type):
        """
        Defines custom fields in the value factory so that the importer can find them
        @param typ
        @param class2type
        """
        field = typ.getField(cls.FIELD_NAME)
        class2type.put( StrStrHashMap , typ )
        typ.setComponentType( StrStrHashMap )
        typ.setImportExportHelper( StrStrHashMapSerializer(typ, field))
        typ.putValidator(field, Validator_object.get(1))
        typ.lock()
def airgap(airgap, ax=0):
    """creates plot of flux density in airgap"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Airgap Flux Density [T]')
    ax.plot(airgap['pos'], airgap['B'],
            label='Max {:4.2f} T'.format(max(airgap['B'])))
    ax.plot(airgap['pos'], airgap['B_fft'],
            label='Base Ampl {:4.2f} T'.format(airgap['Bamp']))
    ax.set_xlabel('Position/°')
    ax.legend()
    ax.grid(True)