code: def lowercase(s: TextSeries) -> TextSeries:
      """
      Lowercase all texts in a series.
  
  
      Examples
      --------
      >>> import texthero as hero
      >>> import pandas as pd
      >>> s = pd.Series("This is NeW YoRk wIth upPer letters")
      >>> hero.lowercase(s)
      0    this is new york with upper letters
      dtype: object
      """
      return s.str.lower()
  
imports: from gensim.models.phrases import Phrases
  import re
  import string
  from typing import Optional, Set
  import unicodedata
  import numpy
  import pandas
  from texthero._types import TokenSeries, TextSeries, InputSeries
  from typing import List, Callable, Union
  import warnings
label_desc: Use image node_id 2 for calling a global function with example usage: lowercase(s) and returns: s