':param http_resp: A http response object that contains a document of
type HTML / PDF / WML / etc.
:return: True if the document parameter is a string that contains an
HTML document. Since we\'re trying to extract as many links as
possible, and the internet is an ugly place (where content
type headers are not mandatory) we\'ll be very forgiving and
return True when we\'re unsure about the content-type.'

@staticmethod
def can_parse(http_resp):

    content_type = http_resp.content_type.lower()
    if (content_type == ''):
        return True
    if (content_type in HTMLParser.SPECIFIC_ACCEPT_CONTENT_TYPES):
        return True
    try:
        (ct_type, ct_subtype) = content_type.split('/')
    except ValueError:
        return False
    if ct_subtype.startswith('vnd.'):
        return False
    if (ct_type in HTMLParser.WILD_ACCEPT_CONTENT_TYPES):
        return True
    if (ct_type in HTMLParser.IGNORE_CONTENT_TYPES):
        return False
    return False
