A testing environment and a method for telephone number identification andor verification. For one embodiment, an apparatus includes an optical waveguide having adjoining first and second regions disposed in semiconductor material. A preferred embodiment of the instrument is an endodontic file for use in the cleaning, shaping, and widening stages of a root canal procedure. These techniques further enhance the accuracy and usability of relevance feedback. A tab is disposed on the first segmented electrode of each set of segmented electrodes. In addition, a pump portion is capable of being driven by the driving force to alternately change an internal pressure of the developer accommodating portion between a pressure lower than an ambient pressure and a pressure higher than the ambient pressure to discharge the developer through the discharge opening.