code: public float dot(Quaternionf otherQuat) {
          return this.x * otherQuat.x + this.y * otherQuat.y + this.z * otherQuat.z + this.w * otherQuat.w;
      }
docs: Return the dot of this quaternion and <code>otherQuat</code>.
  
  @param otherQuat
  the other quaternion
  @return the dot product