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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 create_cluster(cluster_dict, datacenter=None, cluster=None,
                   service_instance=None):
    '''
    Creates a cluster.

    Note: cluster_dict['name'] will be overridden by the cluster param value

    config_dict
        Dictionary with the config values of the new cluster.

    datacenter
        Name of datacenter containing the cluster.
        Ignored if already contained by proxy details.
        Default value is None.

    cluster
        Name of cluster.
        Ignored if already contained by proxy details.
        Default value is None.

    service_instance
        Service instance (vim.ServiceInstance) of the vCenter.
        Default is None.

    .. code-block:: bash

        # esxdatacenter proxy
        salt '*' vsphere.create_cluster cluster_dict=$cluster_dict cluster=cl1

        # esxcluster proxy
        salt '*' vsphere.create_cluster cluster_dict=$cluster_dict
    '''
    # Validate cluster dictionary
    schema = ESXClusterConfigSchema.serialize()
    try:
        jsonschema.validate(cluster_dict, schema)
    except jsonschema.exceptions.ValidationError as exc:
        raise InvalidConfigError(exc)
    # Get required details from the proxy
    proxy_type = get_proxy_type()
    if proxy_type == 'esxdatacenter':
        datacenter = __salt__['esxdatacenter.get_details']()['datacenter']
        dc_ref = _get_proxy_target(service_instance)
        if not cluster:
            raise ArgumentValueError('\'cluster\' needs to be specified')
    elif proxy_type == 'esxcluster':
        datacenter = __salt__['esxcluster.get_details']()['datacenter']
        dc_ref = salt.utils.vmware.get_datacenter(service_instance, datacenter)
        cluster = __salt__['esxcluster.get_details']()['cluster']

    if cluster_dict.get('vsan') and not \
       salt.utils.vsan.vsan_supported(service_instance):

        raise VMwareApiError('VSAN operations are not supported')
    si = service_instance
    cluster_spec = vim.ClusterConfigSpecEx()
    vsan_spec = None
    ha_config = None
    vsan_61 = None
    if cluster_dict.get('vsan'):
        # XXX The correct way of retrieving the VSAN data (on the if branch)
        #  is not supported before 60u2 vcenter
        vcenter_info = salt.utils.vmware.get_service_info(si)
        if float(vcenter_info.apiVersion) >= 6.0 and \
                int(vcenter_info.build) >= 3634794:  # 60u2
            vsan_spec = vim.vsan.ReconfigSpec(modify=True)
            vsan_61 = False
            # We need to keep HA disabled and enable it afterwards
            if cluster_dict.get('ha', {}).get('enabled'):
                enable_ha = True
                ha_config = cluster_dict['ha']
                del cluster_dict['ha']
        else:
            vsan_61 = True
    # If VSAN is 6.1 the configuration of VSAN happens when configuring the
    # cluster via the regular endpoint
    _apply_cluster_dict(cluster_spec, cluster_dict, vsan_spec, vsan_61)
    salt.utils.vmware.create_cluster(dc_ref, cluster, cluster_spec)
    if not vsan_61:
        # Only available after VSAN 61
        if vsan_spec:
            cluster_ref = salt.utils.vmware.get_cluster(dc_ref, cluster)
            salt.utils.vsan.reconfigure_cluster_vsan(cluster_ref, vsan_spec)
        if enable_ha:
            # Set HA after VSAN has been configured
            _apply_cluster_dict(cluster_spec, {'ha': ha_config})
            salt.utils.vmware.update_cluster(cluster_ref, cluster_spec)
            # Set HA back on the object
            cluster_dict['ha'] = ha_config
    return {'create_cluster': True}