code: public static Double getMinY(Geometry geom) {
          if (geom != null) {
              return geom.getEnvelopeInternal().getMinY();
          } else {
              return null;
          }
      }
docs: Returns the minimal y-value of the given geometry.
  
  @param geom Geometry
  @return The minimal y-value of the given geometry, or null if the geometry is null.