InsertImpl extends BaseSqlPart implements Insert { @Nullable @Override public SqlPart previous() { return null; }  @Override void prependTo(@NotNull final RawSqlBuilder builder); @Nullable @Override SqlPart previous(); @NotNull @Override Into into(@NotNull final String tableName); @NotNull @Override Into into(@Nullable final String databaseName, @NotNull final String tableName);  }
@Test public void previous_returnsNullValue() { InsertImpl insert = new InsertImpl(); SqlPart result = insert.previous(); assertThat(result, is(nullValue())); }