def _get_sanitized_version(version_string):
    """
	Removes "-..." prefix from version strings.

	Tests:
	    >>> _get_sanitized_version(None)
	    >>> _get_sanitized_version("1.2.15")
	    '1.2.15'
	    >>> _get_sanitized_version("1.2.15-dev12")
	    '1.2.15'
	"""
    if version_string is not None and '-' in version_string:
        version_string = version_string[:version_string.find('-')]
    return version_string
