private GenericContainer<?> startContainerWithCommand(String shellCommand) {
        return startContainerWithCommand(shellCommand, buildWaitStrategy(ready));
    }
Starts a GenericContainer with the Alpine image, passing the given {@code shellCommand} as
a parameter to {@literal sh -c} (the container CMD).

@param shellCommand the shell command to execute
@return the (unstarted) container
core/src/test/java/org/testcontainers/junit/wait/strategy/AbstractWaitStrategyTest.java