public Builder setStartPeriod(Duration startPeriod) {
      this.startPeriod = startPeriod;
      return this;
    }
Sets the initialization time to wait before using healthchecks.

@param startPeriod the duration to wait before using healthchecks
@return this
jib-core/src/main/java/com/google/cloud/tools/jib/configuration/DockerHealthCheck.java