vcsim fails to mark VM as template

[Akasurde]

I am unable to mark VM as template using vcsim created VM.

Request: <?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Body><MarkAsTemplate xmlns="urn:vim25"><_this type="VirtualMachine">vm-61</_this></MarkAsTemplate></soapenv:Body>
</soapenv:Envelope>
2017/12/14 18:54:06 VirtualMachine:vm-61 does not implement: MarkAsTemplate
Response: <?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><soapenv:Body><soapenv:Fault><faultcode>ServerFaultCode</faultcode><faultstring>VirtualMachine:vm-61 does not implement: MarkAsTemplate</faultstring><detail><Fault xmlns:XMLSchema-instance="http://www.w3.org/2001/XMLSchema-instance" XMLSchema-instance:type="MethodNotFound"><receiver type="VirtualMachine">vm-61</receiver><method>MarkAsTemplate</method></Fault></detail></soapenv:Fault></soapenv:Body></soapenv:Envelope>

Python Traceback

python mark_vm_as_template.py
Traceback (most recent call last):
  File "mark_vm_as_template.py", line 11, in <module>
    vm.MarkAsTemplate()
  File "/Volumes/data/src/ansible/venv4/lib/python2.7/site-packages/pyVmomi/VmomiSupport.py", line 580, in <lambda>
    self.f(*(self.args + (obj,) + args), **kwargs)
  File "/Volumes/data/src/ansible/venv4/lib/python2.7/site-packages/pyVmomi/VmomiSupport.py", line 386, in _InvokeMethod
    return self._stub.InvokeMethod(self, info, args)
  File "/Volumes/data/src/ansible/venv4/lib/python2.7/site-packages/pyVmomi/SoapAdapter.py", line 1357, in InvokeMethod
    raise exc
pyVmomi.SoapAdapter.ParserError: 'xml document: <httplib.HTTPResponse instance at 0x10873ecf8> parse error at: line:2, col:507'

Python reproducer

from pyVmomi import vim
from vm_lib import get_obj, connect

content = connect()

vm = get_obj(content, [vim.VirtualMachine], 'DC0_H0_VM0')
vm.MarkAsTemplate()