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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def is_hyper():
    '''
    Returns a bool whether or not this node is a hypervisor of any kind

    CLI Example:

    .. code-block:: bash

        salt '*' virt.is_hyper
    '''
    try:
        if __grains__['virtual_subtype'] != 'Xen Dom0':
            return False
    except KeyError:
        # virtual_subtype isn't set everywhere.
        return False
    try:
        with salt.utils.files.fopen('/proc/modules') as fp_:
            if 'xen_' not in salt.utils.stringutils.to_unicode(fp_.read()):
                return False
    except (OSError, IOError):
        return False
    # there must be a smarter way...
    return 'xenstore' in __salt__['cmd.run'](__grains__['ps'])