old_contents: from sequana.viz import Volcano
  
  def test1():
      import numpy as np
      fc = np.random.randn(1000)
      pvalue = np.random.randn(1000)
      v = Volcano(fc, -np.log10(pvalue**2), pvalue_threshold=3)
      v.plot()
      v.plot(logy=True)
  
  
  
new_contents: from sequana.viz import Volcano
  import pandas as pd
  
  
  def test1():
      import numpy as np
  
      fc = np.random.randn(1000)
      pvalue = np.random.randn(1000)
      df = pd.DataFrame({"log2FoldChange": fc, "padj": pvalue ** 2})
      v = Volcano(data=df, pvalue_threshold=3)
      v.plot()
      v.plot(logy=True)
  
subject: Update test for volcano plot