====== GetTradingPartnerGLN ======

This function returns the GLN of the trading partner. When you call the function without parameters, the trading partner of the current document is used. If you pass a GLN, the location will be searched by the GLN and then the GLN of the partner will be returned. 

==== Syntax: ====

<code>GetTradingPartnerGLN(['LocationGLN'])</code>

==== Sample: ====

<code>GetTradingPartnerGLN()</code>
<code>GetTradingPartnerGLN('4043077000005')</code>