Convert this Java code to Ruby, please.

//Define the class Card. public class Card //Define the enumerated class Color, Shape, and Fill //to get the card's fear-tures. public enum Color IRED, PURPLE, GREEN public enum Shape sOVAL, SQUARE, DIAMOND; public enum Fill {SOLID, HATCHED, OUTLINE //Declare the required member variables private int rank Of Card; private Color card color; private Shape card shape; private Fill fill card; /Define the constructor of the class. public Card (int cardRank, Color col, Shape sh, Fill fil) this. rank of Card = cardRank; this. ca rd color = col; this.card shapesh; this.fill card fil; //Define the method toString () to reperesent a card //on the board. public String toString return rank Of Card +""+ card color+"+ card shape +""+ fill card,; //Define the method checkSet (). public static boolean checkSet (Card card one, Card card two, Card card three) //Initialize the required variables. boolean rank status = false; boolean color status = false; boolean shape status = false; boolean fill status false; //If rank of each card is same, then set the //rank status true //Define the class Card. public class Card //Define the enumerated class Color, Shape, and Fill //to get the card's fear-tures. public enum Color IRED, PURPLE, GREEN public enum Shape sOVAL, SQUARE, DIAMOND; public enum Fill {SOLID, HATCHED, OUTLINE //Declare the required member variables private int rank Of Card; private Color card color; private Shape card shape; private Fill fill card; /Define the constructor of the class. public Card (int cardRank, Color col, Shape sh, Fill fil) this. rank of Card = cardRank; this. ca rd color = col; this.card shapesh; this.fill card fil; //Define the method toString () to reperesent a card //on the board. public String toString return rank Of Card +""+ card color+"+ card shape +""+ fill card,; //Define the method checkSet (). public static boolean checkSet (Card card one, Card card two, Card card three) //Initialize the required variables. boolean rank status = false; boolean color status = false; boolean shape status = false; boolean fill status false; //If rank of each card is same, then set the //rank status true