def get_next_dev_version(current_version, version_increment_strategy, incremental_release=False):
    """
    Returns the next development version to use. The development version
    always ends with "-SNAPSHOT".

    If incremental_release is False:
        Increments and returns current_version using the specified
        version_increment_strategy.

    If incremental_release is True:
        Returns the current version (because it hasn't been released yet)
    """
    if current_version is None:
        return None
    if incremental_release:
        next_version = current_version
    else:
        next_version = version_increment_strategy(current_version)
    if not next_version.endswith("-SNAPSHOT"):
        next_version += "-SNAPSHOT"
    return next_version