code: def round_nom_time(dt, time_delta):
      """Round a datetime object to a multiple of a timedelta.
  
      dt : datetime.datetime object, default now.
      time_delta : timedelta object, we round to a multiple of this, default 1 minute.
      adapted for SEVIRI from:
      https://stackoverflow.com/questions/3463930/how-to-round-the-minute-of-a-datetime-object-python
      """
      seconds = (dt - dt.min).seconds
      round_to = time_delta.total_seconds()
  
      rounding = (seconds + round_to / 2) // round_to * round_to
  
      return dt + timedelta(0, rounding - seconds, -dt.microsecond)
  
imports: from __future__ import annotations
  import warnings
  from datetime import datetime, timedelta
  import dask.array
  import numpy
  import pyproj
  from numpy.polynomial.chebyshev import Chebyshev
  from satpy.readers.eum_base import issue_revision, time_cds_short
  from satpy.readers.utils import apply_earthsun_distance_correction
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 16 for calling a global function with example usage: round_nom_time(dt, time_delta) and returns: unknown