Initialize default values for each instrumentation type.
Initialize default values for each instrumentation type.

tlunter/oboe-ruby,boyang-li/oboe-ruby,boyang-li/oboe-ruby,boyang-li/oboe-ruby,boyang-li/oboe-ruby,appneta/ruby-traceview,appneta/ruby-traceview,tlunter/oboe-ruby,appneta/ruby-traceview,appneta/ruby-traceview,tlunter/oboe-ruby,tlunter/oboe-ruby