<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def setuptools_install_options(local_storage_folder):

 """
 Return options to make setuptools use installations from the given folder.
 
 No other installation source is allowed.
 
 """

    if local_storage_folder is None:
        return []
    # setuptools expects its find-links parameter to contain a list of link
    # sources (either local paths, file: URLs pointing to folders or URLs
    # pointing to a file containing HTML links) separated by spaces. That means
    # that, when specifying such items, whether local paths or URLs, they must
    # not contain spaces. The problem can be worked around by using a local
    # file URL, since URLs can contain space characters encoded as '%20' (for
    # more detailed information see below).
    #
    # Any URL referencing a folder needs to be specified with a trailing '/'
    # character in order for setuptools to correctly recognize it as a folder.
    #
    # All this has been tested using Python 2.4.3/2.4.4 & setuptools 1.4/1.4.2
    # as well as Python 3.4 & setuptools 3.3.
    #
    # Supporting paths with spaces - method 1:
    # ----------------------------------------
    # One way would be to prepare a link file and pass an URL referring to that
    # link file. The link file needs to contain a list of HTML link tags
    # (<a href="..."/>), one for every item stored inside the local storage
    # folder. If a link file references a folder whose name matches the desired
    # requirement name, it will be searched recursively (as described in method
    # 2 below).
    #
    # Note that in order for setuptools to recognize a local link file URL
    # correctly, the file needs to be named with the '.html' extension. That
    # will cause the underlying urllib2.open() operation to return the link
    # file's content type as 'text/html' which is required for setuptools to
    # recognize a valid link file.
    #
    # Supporting paths with spaces - method 2:
    # ----------------------------------------
    # Another possible way is to use an URL referring to the local storage
    # folder directly. This will cause setuptools to prepare and use a link
    # file internally - with its content read from a 'index.html' file located
    # in the given local storage folder, if it exists, or constructed so it
    # contains HTML links to all top-level local storage folder items, as
    # described for method 1 above.
    if " " in local_storage_folder:
        find_links_param = utility.path_to_URL(local_storage_folder)
        if find_links_param[-1] != "/":
            find_links_param += "/"
    else:
        find_links_param = local_storage_folder
    return ["-f", find_links_param, "--allow-hosts=None"]