text: """ Grids """
  __all__ = ['Grid', 'sample']
  from .grid import Grid
  
  
  def sample(topology='triangular', filename="sphere-h-0.4.msh"):
      """ Convenience function to access the sample grids """
      from os.path import join, exists
      from ..config import paths
      filename = join(paths.meshes, filename)
      if not exists(filename):
          raise IOError("Mesh %s does not exist" % filename)
      return Grid(topology="triangular", filename=filename)
  