import java.io.*;
import java.util.*;

public class Relation {
  // Name of the relation.
  private String name;

  // Attribute names for the relation
  private ArrayList<String> attributes;

  // Domain classes or types of attributes; possible values: INTEGER, DECIMAL, VARCHAR
  private ArrayList<String> domains;

  // Actual data storage (list of tuples) for the relation.
  private ArrayList<Tuple> table;

  // METHODS

  // Constructor; set instance variables
  public Relation (String name, ArrayList<String> attributes, ArrayList<String> dNames) {

  };

  // returns true if attribute with name aname exists in relation schema
  // false otherwise
  public boolean attributeExists(String aname) {

  }

  // returns domain type of attribute aname; return null if not present
  public String attributeType(String aname) {

  }

  // Print relational schema to screen.
  public void displaySchema() {

  }

  // Set name of relation to rname
  public void setName(String rname) {

  }

  // Add tuple tup to relation; Duplicates are fine.
  public void addTuple(Tuple tup) {

  }

  // Print relation to screen (see output of run for formatting)
  public void displayRelation() {

  }

  // Return String version of relation; See output of run for format.
  public String toString() {

  }

}