How do i access the information in an hl7 message parsed with nHapi

I am learning how to use nHapi. As many have pointed out, there's not much documentation. Following this doc I've been able to parse a message using the library. But I can't figure out how to access that message using an object model (which is what I really want nHapi to do). Essentially, I want to take an HL7 message as a string and access it using the object model, in the same way that LINQ to SQL takes a database record and lets you access it as an object. I found Parsing an HL7 without apriori messageType knowledge, but it seems to be about something else because the code in the post returns a string instead of an HL7 object (like I need). In the documentation I linked to above they seem to access the parts of a message using a "query"--but I can't find the materials to query IMessages in the library.

Here is the code I'm using, with a line showing what I want to do...

Imports NHapi.Base
Imports NHapi.Base.Parser
Imports NHapi.Base.Model

Module Module1
 
 Sub Main()
 
     Dim msg As String = "MSH|^~\&|SENDING|SENDER|RECV|INST|20060228155525||QRY^R02^QRY_R02|1|P|2.3|QRD|20060228155525|R|I||||10^RD&Records&0126|38923^^^^^^^^&INST|||"
     Dim myPipeParser As PipeParser = New PipeParser()
     Dim myImsg As IMessage = myPipeParser.Parse(msg)
     Dim msgType As String = myImsg.GetStructureName
     Dim mySendingFacilityName As String = myImsg.getSendingFacility()  //this is what I want
 
 End Sub
 

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