new_contents: 
  import matplotlib.pyplot as plt
  from dovseries import DovGroundwater
  
  
  dov = DovGroundwater("../exampleXML/1-0709.xml")
  dov.peilmetingen.plot()
  
  dov.peilmetingen_timeseries.resample('A').mean().plot()
  
  print(dov.peilmetingen.head())
  print(dov.observaties.head())
  print(dov.metadata_locatie)
  print(dov.metadata_filters['1'])
  print(dov.peilmetingen.shape)
  
  
  dov.peilmetingen.reset_index().pivot_table(index="datum",
                                             columns=["grondwaterlocatie",
                                                      "filternummer"],
                                             values="diepte").plot()
  
  
  dov.observaties.pivot_table(index="datum",
                              columns=["parameter"],
                              values="waarde").plot()
  
  
  dov.get_parameter_series("NO3").plot(kind='barh')
  plt.tight_layout()
  
  plt.show()
subject: add first draft example of some functions