<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def from_text(text, origin = None, rdclass = dns.rdataclass.IN, relativize = True, zone_factory=Zone, filename=None, allow_include=False, check_origin=True):
 """Build a zone object from a master file format string. @param text: the master file format input @type text: string. @param origin: The origin of the zone; if not specified, the first $ORIGIN statement in the master file will determine the origin of the zone. @type origin: dns.name.Name object or string @param rdclass: The zone's rdata class; the default is class IN. @type rdclass: int @param relativize: should names be relativized? The default is True @type relativize: bool @param zone_factory: The zone factory to use @type zone_factory: function returning a Zone @param filename: The filename to emit when describing where an error occurred; the default is '<string>'. @type filename: string @param allow_include: is $INCLUDE allowed? @type allow_include: bool @param check_origin: should sanity checks of the origin node be done? The default is True. @type check_origin: bool @raises dns.zone.NoSOA: No SOA RR was found at the zone origin @raises dns.zone.NoNS: No NS RRset was found at the zone origin @rtype: dns.zone.Zone object """


    # 'text' can also be a file, but we don't publish that fact
    # since it's an implementation detail.  The official file
    # interface is from_file().

    if filename is None:
        filename = '<string>'
    tok = dns.tokenizer.Tokenizer(text, filename)
    reader = _MasterReader(tok, origin, rdclass, relativize, zone_factory,
                           allow_include=allow_include,
                           check_origin=check_origin)
    reader.read()
    return reader.zone