hpack/src/main/java/com/twitter/hpack/DynamicTable.java
public HeaderField remove() {
    HeaderField removed = headerFields[tail];
    if (removed == null) {
      return null;
    }
    size -= removed.size();
    headerFields[tail++] = null;
    if (tail == headerFields.length) {
      tail = 0;
    }
    return removed;
  }
public HeaderField remove() {
    HeaderField removed = headerFields[tail];
    if (removed == null) {
      return null;
    }
    size -= removed.size();
    headerFields[tail++] = null;
    if (tail == headerFields.length) {
      tail = 0;
    }
    return removed;
  }
Remove and return the oldest header field from the dynamic table.