'Delete the rdataset matching the specified properties in the
current node.
If a matching rdataset does not exist, it is not an error.
@param rdclass: The class of the rdataset
@type rdclass: int
@param rdtype: The type of the rdataset
@type rdtype: int
@param covers: The covered type.
@type covers: int'

def delete_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE):

    rds = self.get_rdataset(rdclass, rdtype, covers)
    if (rds is not None):
        self.rdatasets.remove(rds)
