code: public DataSetBuilder sequence(String column, Date initial, int step) {
      ensureArgNotNull(initial);
      return sequence(column, initial, d -> new Date(d.getTime() + step * MILLIS_PER_DAY));
    }
docs: Set {@link Date} sequence filler for column
  with a specified step in days.
  
  <p>
  A call to this method is shorthand for
  <code>sequence(column, initial, d -&gt; new Date(x.getTime() + step * MILLIS_PER_DAY))</code>.
  </p>
  
  @param column Column day.
  @param initial Initial date.
  @param step Step in days.
  @return The builder instance (for chained calls).
  
  @see #sequence(String, Time, int)
  @see #sequence(String, Timestamp, long)
  @see #sequence(String, Object, UnaryOperator)