presto-parser/src/main/java/io/prestosql/sql/tree/DropColumn.java/DropColumn/equals
class DropColumn:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        DropColumn that = (DropColumn) o;
        return Objects.equals(table, that.table) &&
                Objects.equals(column, that.column);
    }