code: function () {
  			var leftNode = this.parseBaseExpression();
  
  			if (this.currentToken.type == 'operator') {
  				var operator = this.currentToken.value;
  				this.readNextToken();
  
  				// If there are 2 adjacent operators, join them with a space (exemple: IS NOT)
  				if (this.currentToken.type == 'operator') {
  					operator += ' ' + this.currentToken.value;
  					this.readNextToken();
  				}
  
  				var rightNode = this.parseBaseExpression();
  
  				leftNode = {'operator': operator, 'left': leftNode, 'right': rightNode};
  			}
  
  			return leftNode;
  		}
docs: Parse conditions ([word/string] [operator] [word/string])