def remove_overlapping_calls(calls):
    """
	Filter a list of variants such that no variants overlap each other.
	This applies mainly to deletions: If they occur too close to another
	variant, the deletion and the other variant are removed.

	This function also guarantees that the positions of the returned variants
	are unique. For that, it may also remove other variants (not necessarily
	involved in a deletion).

	calls -- a list of VcfVariant objects

	Return a list of VcfVariant objects.
	"""
    return calls
