code: def shift_mu(col: pd.Series, perc: float) -> pd.Series:
      """
      Shift the mean of column by a given percentage
  
      Parameters
      ----------
      col : pd.Series
          A Pandas' Series
  
      perc : float
          How much to shift the mu percentually (can be negative)
  
      Returns
      ----------
      A transformed pd.Series
      """
      mu = np.mean(col)
      col = col + mu * perc
      return col
  
file_path: fklearn/src/fklearn/validation/perturbators.py
imports: import random
  from typing import List
  import numpy
  from toolz import curry
  import pandas
  from fklearn.types import ColumnWisePerturbFnType
label_desc: Use image node_id 1 for calling a global function with example usage: shift_mu(col, perc) and returns: col