allow for an empty string to be represented as the default pattern (#547)
allow for an empty string to be represented as the default pattern (#547)


thobbs/ccm,mike-tr-adamson/ccm,tolbertam/ccm,tolbertam/ccm,pcmanus/ccm,mike-tr-adamson/ccm,thobbs/ccm,mikefero/ccm,bcantoni/ccm,pcmanus/ccm,bcantoni/ccm,pcmanus/ccm,mike-tr-adamson/ccm,mikefero/ccm