text: #!/usr/bin/env/python
  """metabolite prediction and plotting tool
  
  VKMZ predicts molecular formulas by searching a known mass-formula dictionary
  for a feature observed by a mass spectrometer. Elemental ratios for predicted-features
  are calculated to create the carbon-to-oxygen and carbon-to-hydrogen axis of a
  van Krevelen Diagram (VKD). VKD's are a convenient visualization tool for
  briefly conveying the constituents of a complex MS mixture (e.g., untargeted
  plant metabolomics). As output predicted-feature are saved to a tabular file,
  an interactive VKD web page, and other optional formats.
  """
  
  # NOTE: reviewers with Python Packaging experience
  #       How do I clean my namespace so that pydoc works on all modules and so
  #       that vkmz is ready for API importation (__all__)?
  #       Wrapping things with if __name__ == __main__ has consequences that may
  #       need to be avoided.
  