def _generate_property(field, template, fname):
    """
    Generate simple function that get/set a field of the instance
    """
    source = template.format(field)
    glbls = {}
    exec(source, glbls)
    return njit(glbls[fname])

    Generate simple function that get/set a field of the instance
    
numba/experimental/jitclass/boxing.py