This class performs the test between two Space Points (usually the target point first and the tentative point second) The function isOK returns TRUE if the two space points are "comparable" with respect to the current criterion Examples:
- if the criterion is based on FAULTS, the method isOK returns TRUE if the two space points are not separated by any fault segment
- if the criterion is based on DISTANCE, the method isOK returns TRUE if the distance between the two space points is smaller than a threshold distance (registered as a member of the BiTargetCheckDistance class)