<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_vm_size_completion_list(cmd, prefix, namespace, **kwargs):
 # pylint: disable=unused-argument """Return the intersection of the VM sizes allowed by the ACS SDK with those returned by the Compute Service."""


    location = _get_location(cmd.cli_ctx, namespace)
    result = get_vm_sizes(cmd.cli_ctx, location)
    return set(r.name for r in result) & set(c.value for c in ContainerServiceVMSizeTypes)