in rules/utils/utils.js [131:140]
function isToStringStatement(node) {
return node.type === 'CallExpression' &&
node.callee.type === 'MemberExpression' &&
node.callee.object.type === 'MemberExpression' &&
node.callee.object.property.name === 'toString' &&
node.callee.property.name === 'call' &&
node.callee.object.object.type === 'MemberExpression' &&
node.callee.object.object.object.name === 'Object' &&
node.callee.object.object.property.name === 'prototype';
}