public Builder setFormat(ImageFormat format) {
      this.format = format;
      return this;
    }
Sets the format to build the container image as. Use {@link ImageFormat#Docker} for Docker
V2.2 or {@link ImageFormat#OCI} for OCI.

@param format the {@link ImageFormat}
@return this
jib-build-plan/src/main/java/com/google/cloud/tools/jib/api/buildplan/ContainerBuildPlan.java