code: public Envelope createEnvelope(double[] coordinates)
              throws TypeConversionException {
          if (coordinates.length < 4) {
              throw new TypeConversionException("Not enough coordinates in inputstring");
          } else {
              double minX = Double.MAX_VALUE;
              double minY = Double.MAX_VALUE;
              double maxX = Double.MIN_VALUE;
              double maxY = Double.MIN_VALUE;
              for (int i = 0 ; i < coordinates.length; i++){
                  if (i % 2 == 0) {
                      if (coordinates[i] < minX) minX = coordinates[i];
                      if (coordinates[i] > maxX) maxX = coordinates[i];
                  } else {
                      if (coordinates[i] < minY) minY = coordinates[i];
                      if (coordinates[i] > maxY) maxY = coordinates[i];
                  }
              }
              return new Envelope(minX, minY, maxX, maxY);
          }
      }
docs: Creates an envelope based on a list of coordinates. If less than two coordinates are in the list,
  a typeconversion exception is thrown. If more than two coordinates are in the list, the minimum X- and
  Y-coordinates are searched.
  
  @param coordinates A list with the coordinates of the envelope
  @return An envelope with the given coordinates
  @throws TypeConversionException If the creation of the envelope failed