Microbenchmarks for parts of the Beam SDK

To run benchmarks:

1. Run mvn install in the top directory to install the SDK.

2. Build the benchmark package:

   cd microbenchmarks
   mvn package
   

3. run benchmark harness:

   java -jar target/microbenchmarks.jar
   

4. (alternate to step 3) to run just a subset of benchmarks, pass a regular expression that matches the benchmarks you want to run (this can match against the class name, or the method name). E.g., to run any benchmarks with “DoFnReflector” in the name:

   java -jar target/microbenchmarks.jar ".*DoFnReflector.*"