How to use the smmap.SlidingWindowMapManager function in smmap

import errno

from io import BytesIO

from smmap import (
    StaticWindowMapManager,
    SlidingWindowMapManager,
    SlidingWindowMapBuffer
)

# initialize our global memory manager instance
# Use it to free cached (and unused) resources.
if sys.version_info < (2, 6):
    mman = StaticWindowMapManager()
else:
    mman = SlidingWindowMapManager()
# END handle mman

import hashlib

try:
    from struct import unpack_from
except ImportError:
    from struct import unpack, calcsize
    __calcsize_cache = dict()

    def unpack_from(fmt, data, offset=0):
        try:
            size = __calcsize_cache[fmt]
        except KeyError:
            size = calcsize(fmt)
            __calcsize_cache[fmt] = size

import mmap
import sys
import time
import errno

from io import BytesIO

from smmap import (
    StaticWindowMapManager,
    SlidingWindowMapManager,
    SlidingWindowMapBuffer
)

# initialize our global memory manager instance
# Use it to free cached (and unused) resources.
mman = SlidingWindowMapManager()
# END handle mman

import hashlib

try:
    from struct import unpack_from
except ImportError:
    from struct import unpack, calcsize
    __calcsize_cache = dict()

    def unpack_from(fmt, data, offset=0):
        try:
            size = __calcsize_cache[fmt]
        except KeyError:
            size = calcsize(fmt)
            __calcsize_cache[fmt] = size