Imports of cmd command

PathSynopsis
cloud.google.com/go/pubsub/loadtestPackage loadtest implements load testing for pubsub, following the interface defined in https://github.com/GoogleCloudPlatform/pubsub/tree/master/load-test-framework/ .
cloud.google.com/go/pubsub/loadtest/pb
flagPackage flag implements command-line flag parsing.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
google.golang.org/grpcPackage grpc implements an RPC system called gRPC.
logPackage log implements a simple logging package.
math/randPackage rand implements pseudo-random number generators suitable for tasks such as simulation, but it should not be used for security-sensitive work.
netPackage net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets.
strconvPackage strconv implements conversions to and from string representations of basic data types.