code: public static BooleanExpression dwithin(Expression<? extends Geometry> expr1,
                                              Expression<? extends Geometry> expr2, Expression<Double> distance) {
          return Expressions.booleanOperation(SpatialOps.DWITHIN, expr1, expr2, distance);
      }
docs: Returns true if the geometries are within the specified distance of one another.
  For geometry units are in those of spatial reference and For geography units are in meters.
  
  @param expr1 geometry
  @param expr2 other geometry
  @param distance distance
  @return true, if with distance of each other