public Builder setEntrypoint(@Nullable List<String> entrypoint) {
      if (entrypoint == null) {
        this.entrypoint = null;
      } else {
        this.entrypoint = new ArrayList<>(entrypoint);
      }
      return this;
    }
Sets the container entrypoint. This is the beginning of the command that is run when the
container starts. {@link #setCmd} sets additional tokens. {@code null} signals to use the
base image value.

<p>This is similar to <a
href="https://docs.docker.com/engine/reference/builder/#exec-form-entrypoint-example">{@code
ENTRYPOINT} in Dockerfiles</a> or {@code command} in the <a
href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#container-v1-core">Kubernetes
Container spec</a>.

@param entrypoint a list of the entrypoint command
@return this
jib-build-plan/src/main/java/com/google/cloud/tools/jib/api/buildplan/ContainerBuildPlan.java