@NonNull
    public Builder addConstraint(@JobConstraint int constraint) {
      // Create a new, longer constraints array
      int[] newConstraints = new int[constraints == null ? 1 : constraints.length + 1];

      if (constraints != null && constraints.length != 0) {
        // Copy all the old values over
        System.arraycopy(constraints, 0, newConstraints, 0, constraints.length);
      }

      // add the new value
      newConstraints[newConstraints.length - 1] = constraint;
      // update the pointer
      constraints = newConstraints;

      return this;
    }
Adds the provided constraint to the current list of runtime constraints.
jobdispatcher/src/main/java/com/firebase/jobdispatcher/Job.java