User-Defined Functions and Function Libraries 
You can create your own user-defined function in Java source code. A user-defined function created in a message mapping or mapping template is stored in a local function library belonging to the corresponding mapping object. To use a user-defined function in more than one message mapping or mapping template, you have the option to create the user-defined functions in function libraries in the ES Repository.
A function library is created and maintained as a separate design object in the ES Repository.
Note
A message mapping can only use function libraries that are defined in the same software component version as the message mapping, or in an underlying version.
End of the note.
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