code: def l2_afr_schema(settings=None):
      """Define schema  for LI L2 AFR product."""
      settings = settings or {}
      nobs = settings.get("num_obs", 120)
      nacc = settings.get("num_accumulations", 20)
  
      return {
          "providers": settings.get("providers", {}),
          "variable_path": settings.get("variable_path", ""),
          "dimensions": accumulation_dimensions(nacc, nobs),
          "variables": {
              "flash_radiance": {
                  "format": "f4",
                  "shape": ("pixels",),
                  "long_name": "Area averaged flash radiance accumulation",
                  "grid_mapping": "mtg_geos_projection",
                  "coordinate": "sparse: x y",
                  "default_data": lambda: np.random.randint(
                      low=1, high=6548, size=(120), dtype=np.int16
                  ),
              },
              "accumulation_start_times": {
                  "format": "f4",
                  "shape": ("accumulations",),
                  "long_name": "Accumulation start time",
                  "units": "seconds since 2000-01-01 00:00:00.0",
                  "default_data": lambda: 0,
              },
              "mtg_geos_projection": mtg_geos_projection(),
              "x": fci_grid_definition("X", nobs),
              "y": fci_grid_definition("Y", nobs),
          },
      }
  
imports: from datetime import datetime
  import numpy
  import xarray
  from satpy.tests.reader_tests.test_netcdf_utils import FakeNetCDF4FileHandler
label_desc: Use image node_id 7 for calling a global function with example usage: l2_afr_schema(settings) and returns: dict