[5.1.0.47 beta] Big Data example throws error when press enter in filter field

http://dev.sencha.com/ext/beta/5.1.0...#big-data-grid

Entering something into the name filter field and then press enter throws this error:

Code:

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Uncaught TypeError: undefined is not a function

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This is a duplicate report of http://www.sencha.com/forum/showthre...ader-filtering