code: def test_drop_duplicates(self):
      pdf = pd.DataFrame(
          {"animal": ["lama", "cow", "lama", "beetle", "lama", "hippo"]}
      )
      psdf = ps.from_pandas(pdf)
  
      pser = pdf.animal
      psser = psdf.animal
  
      self.assert_eq(
          psser.drop_duplicates().sort_index(),
          pser.drop_duplicates().sort_index(),
      )
      self.assert_eq(
          psser.drop_duplicates(keep="last").sort_index(),
          pser.drop_duplicates(keep="last").sort_index(),
      )
  
      # inplace
      psser.drop_duplicates(keep=False, inplace=True)
      pser.drop_duplicates(keep=False, inplace=True)
      self.assert_eq(psser.sort_index(), pser.sort_index())
      self.assert_eq(psdf, pdf)
  
imports: import unittest
  from itertools import product
  import numpy
  import pandas
  from pyspark import pandas
  from pyspark.errors import PySparkValueError
  from pyspark.testing.pandasutils import ComparisonTestBase
  from pyspark.testing.sqlutils import SQLTestUtils
label_desc: Use image node_id 2 for calling the SeriesComputeMixin obj's underlying member method code with example usage: obj.test_drop_duplicates() without return types