GridChildPlacement({int column, int row, int columnSpan: 1, int rowSpan: 1 })

Creates a placement for a child in a grid.

The column and row arguments must not be null. By default, the child spans a single column and row.

Source 

GridChildPlacement({
  this.column,
  this.row,
  this.columnSpan: 1,
  this.rowSpan: 1
}) {
  assert(column != null && column >= 0);
  assert(row != null && row >= 0);
  assert(columnSpan != null && columnSpan > 0);
  assert(rowSpan != null && rowSpan > 0);
}