old_contents: from casexml.apps.case.exceptions import BadVersionException
  
  V1 = "1.0"
  V2 = "2.0"
  DEFAULT_VERSION = V1
  LEGAL_VERSIONS = [V1, V2]
  
  V2_NAMESPACE = "http://commcarehq.org/case/transaction/v2"
  
  NS_VERSION_MAP = {
      V2: V2_NAMESPACE
  }
  
  NS_REVERSE_LOOKUP_MAP = dict((v, k) for k, v in NS_VERSION_MAP.items())
  
  
  def check_version(version):
      if not version in LEGAL_VERSIONS:
          raise BadVersionException(
              "%s is not a legal version, must be one of: %s" %
              (version, ", ".join(LEGAL_VERSIONS))
          )
  
new_contents: from casexml.apps.case.exceptions import BadVersionException
  
  V1 = "1.0"
  V2 = "2.0"
  V3 = "3.0"
  DEFAULT_VERSION = V1
  LEGAL_VERSIONS = [V1, V2, V3]
  
  V2_NAMESPACE = "http://commcarehq.org/case/transaction/v2"
  
  NS_VERSION_MAP = {
      V2: V2_NAMESPACE,
  }
  
  NS_REVERSE_LOOKUP_MAP = dict((v, k) for k, v in NS_VERSION_MAP.items())
  
  
  def check_version(version):
      if not version in LEGAL_VERSIONS:
          raise BadVersionException(
              "%s is not a legal version, must be one of: %s" %
              (version, ", ".join(LEGAL_VERSIONS))
          )
  
subject: add v3