code: def getmode(mode: str) -> ModeDescriptor:
      """Gets a mode descriptor for the given mode."""
      # initialize mode cache
      endian = "<" if sys.byteorder == "little" else ">"
  
      modes = {
          # core modes
          # Bits need to be extended to bytes
          "1": ("L", "L", ("1",), "|b1"),
          "L": ("L", "L", ("L",), "|u1"),
          "I": ("L", "I", ("I",), endian + "i4"),
          "F": ("L", "F", ("F",), endian + "f4"),
          "P": ("P", "L", ("P",), "|u1"),
          "RGB": ("RGB", "L", ("R", "G", "B"), "|u1"),
          "RGBX": ("RGB", "L", ("R", "G", "B", "X"), "|u1"),
          "RGBA": ("RGB", "L", ("R", "G", "B", "A"), "|u1"),
          "CMYK": ("RGB", "L", ("C", "M", "Y", "K"), "|u1"),
          "YCbCr": ("RGB", "L", ("Y", "Cb", "Cr"), "|u1"),
          # UNDONE - unsigned |u1i1i1
          "LAB": ("RGB", "L", ("L", "A", "B"), "|u1"),
          "HSV": ("RGB", "L", ("H", "S", "V"), "|u1"),
          # extra experimental modes
          "RGBa": ("RGB", "L", ("R", "G", "B", "a"), "|u1"),
          "BGR;15": ("RGB", "L", ("B", "G", "R"), "|u1"),
          "BGR;16": ("RGB", "L", ("B", "G", "R"), "|u1"),
          "BGR;24": ("RGB", "L", ("B", "G", "R"), "|u1"),
          "LA": ("L", "L", ("L", "A"), "|u1"),
          "La": ("L", "L", ("L", "a"), "|u1"),
          "PA": ("RGB", "L", ("P", "A"), "|u1"),
      }
      if mode in modes:
          base_mode, base_type, bands, type_str = modes[mode]
          return ModeDescriptor(
              mode, bands, base_mode, base_type, type_str
          )
  
      mapping_modes = {
          # I;16 == I;16L, and I;32 == I;32L
          "I;16": "<u2",
          "I;16S": "<i2",
          "I;16L": "<u2",
          "I;16LS": "<i2",
          "I;16B": ">u2",
          "I;16BS": ">i2",
          "I;16N": endian + "u2",
          "I;16NS": endian + "i2",
          "I;32": "<u4",
          "I;32B": ">u4",
          "I;32L": "<u4",
          "I;32S": "<i4",
          "I;32BS": ">i4",
          "I;32LS": "<i4",
      }
  
      type_str = mapping_modes[mode]
      return ModeDescriptor(mode, ("I",), "L", "L", type_str)
  
imports: from __future__ import annotations
  import sys
  from functools import lru_cache
label_desc: Use image node_id 1 for calling a global function with example usage: getmode(mode) and returns: ModeDescriptor, ModeDescriptor