checkNotNull(equalityGroup);
    List<Object> list = new ArrayList<>(equalityGroup.length);
    for (int i = 0; i < equalityGroup.length; i++) {
      Object element = equalityGroup[i];
      if (element == null) {
        throw new NullPointerException("at index " + i);
      }
      list.add(element);
    }
    equalityGroups.add(list);
    return this;
  }

In this case, `str` is the type parameter passed to `List` (or `list` in Python 3.9 and above).

///

That means: "the variable `items` is a `list`, and each of the items in this list is a `str`".

/// tip

If you use Python 3.9 or above, you don't have to import `List` from `typing`, you can use the same regular `list` type instead.

///

                    populateForRowKeySet(table, elements);
                    return table.rowKeySet();
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    sort(insertionOrder);
                    return insertionOrder;
                  }
                })
            .named("TreeBasedTable.rowKeySet")

                    populateForRowKeySet(table, elements);
                    return table.rowKeySet();
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    sort(insertionOrder);
                    return insertionOrder;
                  }
                })
            .named("TreeBasedTable.rowKeySet")

    return new Colliders();
  }

  @Override
  public Object[] createArray(int length) {
    return new Object[length];
  }

  /** Returns the original element list, unchanged. */
  @Override
  public List<Object> order(List<Object> insertionOrder) {
    return insertionOrder;
  }

                    }
                    if (logger.isDebugEnabled()) {
                        logger.debug(line);
                    }
                    list.add(line);
                    if (list.size() > maxLineBuffer) {
                        list.remove(0);
                    }
                } catch (final IOException e) {
                    throw new CrawlerSystemException(e);
                }
            }

        }
    }

    protected void addFessConfigProperties(final List<String> cmdList) {
        System.getProperties().keySet().stream().filter(k -> k != null && k.toString().startsWith(Constants.FESS_CONFIG_PREFIX))
                .forEach(k -> addSystemProperty(cmdList, k.toString(), null, null));
    }

    protected void addFessSystemProperties(final List<String> cmdList) {

        private final String name;
        private final List<Plugin> plugins;
        private final Collection<Lifecycle.Link> links;
        private final List<Lifecycle.Phase> phases;

        DefaultPhase(
                String name, List<Plugin> plugins, Collection<Lifecycle.Link> links, List<Lifecycle.Phase> phases) {
            this.name = name;
            this.plugins = plugins;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A list which forwards all its method calls to another list. Subclasses should override one or
 * more methods to modify the behavior of the backing list as desired per the <a

   */
  public static List<String> readLines(URL url, Charset charset) throws IOException {
    // don't use asCharSource(url, charset).readLines() because that returns
    // an immutable list, which would change the behavior of this method
    return readLines(
        url,
        charset,
        new LineProcessor<List<String>>() {
          final List<String> result = Lists.newArrayList();

          @Override