function getPropertyName(node) {
      if (node.key || ['MethodDefinition', 'Property'].indexOf(node.type) !== -1) {
        return node.key.name;
      }
      if (node.type === 'MemberExpression') {
        return node.property.name;
      // Special case for class properties
      // (babel-eslint@5 does not expose property name so we have to rely on tokens)
      }
      if (node.type === 'ClassProperty') {
        const tokens = getFirstTokens(context, node, 2);
        return tokens[1] && tokens[1].type === 'Identifier' ? tokens[1].value : tokens[0].value;
      }
      return '';
    }
Get properties name
@param {Object} node - Property.
@returns {string} Property name.