text: import numpy as np
  import matplotlib.pyplot as plt
  import matplotlib.gridspec as gridspec
  
  # ensure tests can import the package
  import sys
  import os
  sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
  
  from nice_orbs.orb_class import BodyOrb
  import nice_orbs.orb_funcs as orb_funcs
  
  # get eccentric anomaly from a mean anomaly
  e = 0.7
  M = np.radians(45)
  E = orb_funcs.E_from_M(M,e)
  print(E)
  