Most of the code for the core Geocell concept was ported from the Java version. The proximity_fetch implementation was ported from the Python version, with the "entity" store abstracted out to remove the coupling to Google App Engine. Also, this proximity_fetch does not directly support the execution of an additional query to filter the promixity results with, though this could be implemented in whatever entity finder function the user passes to it. A geocell is a hexadecimal string that defines a two dimensional rectangular region inside the [-90,90] x [-180,180] latitude/longitude space. A geocell's 'resolution' is its length. For most practical purposes, at high resolutions, geocells can be treated as single points.