code: def leap_year(gyear):
      r"""Determine if this is a Gregorian leap year.
  
      Parameters
      ----------
      gyear : int
          Gregorian year.
  
      Returns
      -------
      leap_year : bool
          True if a Gregorian leap year, else False.
      """
  
      mod1 = gyear % 4 == 0
      mod2 = True
      if gyear % 100 == 0:
          mod2 = gyear % 400 == 0
  
      leap_year = False
      if mod1 and mod2:
          leap_year = True
      return leap_year
  
imports: import calendar
  import logging
  import math
  import pandas
label_desc: Use image node_id 17 for calling a global function with example usage: leap_year(gyear) and returns: leap_year