Check if resource exists in repository

[Adrià Mercader]

Hi everybody,
hope anyone can help me with this,

Is there a way to check if a resource already exists in the repository 
(Session or Library) i.e.
Session:$sessionId/POIs.FeatureSource
or
Library://Barcelona/Data/POIs.FeatureSource

something like:

$rsId = new MgResourceIdentifier(Session:$sessionId/POIs.FeatureSource);

if (! lostFunctionToCheckIfResourceExists($rsId)) {
  createResource();
}

Thanks in advance!

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