code: def get_fourier_col_name(
      k, col_name, function_name="sin", seas_name=None
  ):
      """Returns column name corresponding to a particular fourier term, as returned by fourier_series_fcn
  
      :param k: int
          fourier term
      :param col_name: str
          column in the dataframe used to generate fourier series
      :param function_name: str
          sin or cos
      :param seas_name: strcols_interact
          appended to new column names added for fourier terms
      :return: str
          column name in DataFrame returned by fourier_series_fcn
      """
      # patsy doesn't allow "." in formula term. Replace "." with "_" rather than quoting "Q()" all fourier terms
      name = f"{function_name}{k:.0f}_{col_name}"
      if seas_name is not None:
          name = f"{name}_{seas_name}"
      return name
  
imports: import math
  from datetime import datetime
  from datetime import timedelta
  import numpy
  import pandas
  import pytz
  from holidays_ext import get_holidays
  from pandas.tseries.frequencies import to_offset
  from scipy.special import expit
  from greykite.common import constants
  from greykite.common.python_utils import split_offset_str
label_desc: Use image node_id 26 for calling a global function with example usage: get_fourier_col_name(k, col_name, function_name, seas_name) and returns: name