content: /// Provides metadata and additional contextual information about content posted on Twitter
  abstract class Entity {
    static const START_INDEX = 0;
    static const int END_INDEX = 1;
  
    /// An array of integers indicating the offsets within the Tweet text where the Entity begins and ends.
    ///
    /// Symbols:
    /// The first integer represents the location of the $ character in the Tweet text string.
    /// The second integer represents the location of the first character after the cashtag.
    /// Therefore the difference between the two numbers will be the length of the hashtag name plus one (for the ‘$’ character).
    ///
    /// Urls:
    /// An array of integers representing offsets within the Tweet text where the URL begins and ends.
    /// The first integer represents the location of the first character of the URL in the Tweet text.
    /// The second integer represents the location of the first non-URL character after the end of the URL.
    ///
    /// Hashtags:
    /// An array of integers indicating the offsets within the Tweet text where the hashtag begins and ends.
    /// The first integer represents the location of the # character in the Tweet text string.
    /// The second integer represents the location of the first character after the hashtag.
    /// Therefore the difference between the two numbers will be the length of the hashtag name plus one (for the ‘#’ character).
    ///
    /// Media:
    /// An array of integers indicating the offsets within the Tweet text where the URL begins and ends.
    /// The first integer represents the location of the first character of the URL in the Tweet text.
    /// The second integer represents the location of the first non-URL character occurring after the URL (or the end of the string if the URL is the last part
    /// of the Tweet text).
    ///
    /// User mentions:
    /// An array of integers representing the offsets within the Tweet text where the user reference begins and ends.
    /// The first integer represents the location of the ‘@’ character of the user mention.
    /// The second integer represents the location of the first non-screenname character following the user mention.
    List<int> indices;
  
    Entity({
      required this.indices,
    });
  
    int get start {
      return indices[START_INDEX];
    }
  
    int get end {
      return indices[END_INDEX];
    }
  }
  