Registers a given index:

    * Creates and opens an index for it (if it doesn't exist yet)
    * Sets some default values on it (unless they're already set)

    Args:
        index (PonyWhoosh.Index): An instance of PonyWhoosh.Index class

def register_index(self, index):
    """Registers a given index:

    * Creates and opens an index for it (if it doesn't exist yet)
    * Sets some default values on it (unless they're already set)

    Args:
        index (PonyWhoosh.Index): An instance of PonyWhoosh.Index class
    """

    self._indexes[index._name] = index
    self.create_index(index)
    return index