/**
   * Constructor for nominal attributes and string attributes. If a null vector
   * of attribute values is passed to the method, the attribute is assumed to be
   * a string.
   *
   * @param attributeName the name for the attribute
   * @param attributeValues a vector of strings denoting the attribute values.
   *          Null if the attribute is a string attribute.
   */
  // @ requires attributeName != null;
  // @ ensures m_Name == attributeName;
  public Attribute(String attributeName, List<String> attributeValues) {

    this(attributeName, attributeValues, (ProtectedProperties)null);
  }

  /**
   * Constructor for nominal attributes and string attributes, where metadata is
   * supplied. If a null vector of attribute values is passed to the method, the
   * attribute is assumed to be a string.
   *
   * @param attributeName the name for the attribute
   * @param attributeValues a vector of strings denoting the attribute values.
   *          Null if the attribute is a string attribute.
   * @param metadata the attribute's properties
   */
  // @ requires attributeName != null;
  // @ requires metadata != null;
  /*
   * @ ensures m_Name == attributeName; ensures m_Index == -1; ensures
   * attributeValues == null && m_Type == STRING || attributeValues != null &&
   * m_Type == NOMINAL && m_Values.size() == attributeValues.size(); signals
   * (IllegalArgumentException ex) (* if duplicate strings in attributeValues
   * *);
   */
  public Attribute(String attributeName, List<String> attributeValues,
    ProtectedProperties metadata) {

    m_Name = attributeName;
    m_AttributeInfo = new NominalAttributeInfo(attributeValues, attributeName);
    if (attributeValues == null) {
      m_Type = STRING;
    } else {
      m_Type = NOMINAL;
    }
    if (metadata != null) {
      m_AttributeMetaInfo = new AttributeMetaInfo(metadata, this);
    }
  }