code: ///////////////////////////////////////////////////////////////////////////////
  // For information as to what this class does, see the Javadoc, below.       //
  // Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,       //
  // 2007, 2008, 2009, 2010, 2014, 2015 by Peter Spirtes, Richard Scheines, Joseph   //
  // Ramsey, and Clark Glymour.                                                //
  //                                                                           //
  // This program is free software; you can redistribute it and/or modify      //
  // it under the terms of the GNU General Public License as published by      //
  // the Free Software Foundation; either version 2 of the License, or         //
  // (at your option) any later version.                                       //
  //                                                                           //
  // This program is distributed in the hope that it will be useful,           //
  // but WITHOUT ANY WARRANTY; without even the implied warranty of            //
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
  // GNU General Public License for more details.                              //
  //                                                                           //
  // You should have received a copy of the GNU General Public License         //
  // along with this program; if not, write to the Free Software               //
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA //
  ///////////////////////////////////////////////////////////////////////////////
  
  package edu.cmu.tetrad.graph;
  
  import edu.cmu.tetrad.util.TetradSerializable;
  import java.beans.PropertyChangeListener;
  import java.util.Map;
  
  /**
   * Represents an object with a name, node type, and position that can serve as a
   * node in a graph.
   *
   * @author Joseph Ramsey
   * @see NodeType
   */
  public interface Node extends TetradSerializable, Comparable {
      long serialVersionUID = 23L;
  
      /**
       * @return the name of the node.
       */
      String getName();
  
      /**
       * Sets the name of this node.
       */
      void setName(String name);
  
      /**
       * @return the node type for this node.
       */
      NodeType getNodeType();
  
      /**
       * Sets the node type for this node.
       */
      void setNodeType(NodeType nodeType);
      
      /**
       * 
       * @return the intervention type
       */
      NodeVariableType getNodeVariableType();
  
      /**
       * Sets the type (domain, interventional status, interventional value..) for this node variable
       * @param nodeVariableType 
       */
      void setNodeVariableType(NodeVariableType nodeVariableType);
      
      /**
       * @return a string representation of the node.
       */
      String toString();
  
      /**
       * @return the x coordinate of the center of the node.
       */
      int getCenterX();
  
      /**
       * Sets the x coordinate of the center of this node.
       */
      void setCenterX(int centerX);
  
      /**
       * @return the y coordinate of the center of the node.
       */
      int getCenterY();
  
      /**
       * Sets the y coordinate of the center of this node.
       */
      void setCenterY(int centerY);
  
      /**
       * Sets the (x, y) coordinates of the center of this node.
       */
      void setCenter(int centerX, int centerY);
  
      /**
       * Adds a property change listener.
       */
      void addPropertyChangeListener(PropertyChangeListener l);
  
      /**
       * @return a hashcode for this variable.
       */
      int hashCode();
  
      /**
       * @return true iff this variable is equal to the given variable.
       */
      boolean equals(Object o);
  
      /**
       * Creates a new node of the same type as this one with the given name.
       */
      Node like(String name);
  
      /**
       * Alphabetical order.
       */
      int compareTo(Object o);
      
      Map<String, Object> getAllAttributes();
      
      Object getAttribute(String key);
      
      void removeAttribute(String key);
      
      void addAttribute(String key, Object value);
  
  }
  
  
  
  
  
  