-- Executing [1234@pre-process:1] SIPAddHeader("SIP/mysite.tld-0916c810", "X-Header-1: test1") in new stack
    -- Executing [1234@pre-process:2] SIPAddHeader("SIP/mysite.tld-0916c810", "X-Header-2: test2") in new stack
    -- Executing [1234@pre-process:3] NoOp("SIP/mysite.tld-0916c810", "Header1: X-Header-2: test2 Header2: ") in new stack
    -- Executing [1234@pre-process:4] Dial("SIP/mysite.tld-0916c810", "SIP/1234@peer") in new stack
    -- Called 1234@peer
    -- SIP/peer-09186590 is ringing
  == Spawn extension (pre-process, 1234, 4) exited non-zero on 'SIP/mysite.tld-0916c810'