How to use the vivisect.const.L_VA function in vivisect

def get_strings(vw):
    '''
    enumerate the strings in the given vivisect workspace.

    Args:
      vw (vivisect.Workspace): the workspace.

    Yields:
      Tuple[int, str]: the address, string pair.
    '''
    for loc in vw.getLocations(ltype=vivisect.const.LOC_STRING):
        va = loc[vivisect.const.L_VA]
        size = loc[vivisect.const.L_SIZE]
        yield va, vw.readMemory(va, size).decode('ascii')

    for loc in vw.getLocations(ltype=vivisect.const.LOC_UNI):
        va = loc[vivisect.const.L_VA]
        size = loc[vivisect.const.L_SIZE]
        try:
            yield va, vw.readMemory(va, size).decode('utf-16le')
        except UnicodeDecodeError:
            continue