Challenge Not yet complete... here's what's wrong: 
The campingList component doesn't appear to have a Packed checkbox field in the form using a Lightning Base component.

Continue to receive this error on the Trailhead even though the packed checkbox field is there.  Here are the two relevant Lightning components.  Obviously, Trailhead is looking for a certain parameter or attribute that is missing but is not specified what exactly it is looking for.  Any help would be appreciated.
 

Camping List
<aura:component >
    <aura:handler name="addItemEvent" event="c:addItemEvent"
                  action="{!c.handleAddItem}"/>
    <aura:attribute name="items" type="Camping_Item__c[]"/>
    <aura:attribute name="newItem" type="Camping_Item__c"
                    default="{'sobjectType' : 'Camping_Item__c',
                               'Quantity__c' : 0,
                               'Price__c' : 0}"/>
    <!-- BOXED AREA -->
    <fieldset class="slds-box slds-theme--default slds-container--small">

        <legend id="newCampItemForm" class="slds-text-heading--small
      slds-p-vertical--medium">
            Add Camping Item
        </legend>

        <!-- CREATE NEW CAMPING ITEM FORM -->
        <form class="slds-form--stacked">

            <div class="slds-form-element slds-is-required">
                <div class="slds-form-element__control">
                    <lightning:input type="text" aura:id="itemform" label="Camping Item Name"
                                  value="{!v.newItem.Name}"
                                  required="true"/>
                </div>
            </div>

            <div class="slds-form-element slds-is-required">
                <div class="slds-form-element__control">
                    <lightning:input type="number" aura:id="itemform" label="Quantity"
                                     name="itemform"
                                     min="1"
                                     step="1"
                                     value="{!v.newItem.Quantity__c}"
                                     placeholder="0"/>

                </div>
            </div>

            <div class="slds-form-element">
                <div class="slds-form-element__control">
                    <lightning:input type="number" aura:id="itemform" label="Price"
                                      value="{!v.newItem.Price__c}"/>
                </div>
            </div>

            <div class="slds-form-element">
                <lightning:input type="checkbox" aura:id="itemform" label="Packed?"
                                  value="{!v.newItem.Packed__c}"/>
            </div>

            <div class="slds-form-element">
                <lightning:button label="Create Camping Item"
                           class="slds-button slds-button--brand"
                           onclick="{!c.clickCreateItem}"/>
            </div>

        </form>
        <!-- / CREATE NEW CAMPING ITEM FORM -->

    </fieldset>
    <!--<div class ="slds-card slds-p-top&#45;&#45;meduim">-->
        <!--<header class ="slds-card__header">-->
            <!--<h3 class = "slds-text-heading&#45;&#45;small">Items</h3>-->
        <!--</header>-->

        <!--<section class ="slds-card__body">-->
            <!--<div id="list" class = "row">-->
                <!--<aura:iteration items="{!v.items}" var="item">-->
                    <!--<c:campingListItem item="{!item}"/>-->
                <!--</aura:iteration>-->
            <!--</div>-->
        <!--</section>-->
    <!--</div>-->
    <!-- i do not think this html is needed any longer -->
    <c:campingListForm />
</aura:component>

 

Camping List Form
<aura:component >

    <aura:attribute name="newItem" type="Camping_Item__c"
                    default="{ 'sobjectType': 'Camping_Item__c',
                    'Name': '',
                    'Packed__c': false,
                    'Price__c': '0',
                    'Quantity__c': '0' }"/>
    <aura:registerEvent name="addItem" type="c:addItemEvent"/>

    <div>
        <form class="slds-form--stacked">

            <div class="slds-form-element slds-is-required">
                <div class="slds-form-element__control">
                    <lightning:input type="text" aura:id="itemform" label="Camping Item Name"
                                     value="{!v.newItem.Name}"
                                     required="true"/>
                </div>
            </div>

            <div class="slds-form-element slds-is-required">
                <div class="slds-form-element__control">
                    <lightning:input type="number" aura:id="itemform" label="Quantity"
                                     name="itemform"
                                     min="1"
                                     step="1"
                                     value="{!v.newItem.Quantity__c}"
                                     placeholder="0"/>

                </div>
            </div>

            <div class="slds-form-element">
                <div class="slds-form-element__control">
                    <lightning:input type="number" aura:id="itemform" label="Price"
                                     value="{!v.newItem.Price__c}"/>
                </div>
            </div>

            <div class="slds-form-element">
                <lightning:input type="checkbox" aura:id="itemform" label="Packed?"
                                 value="{!v.newItem.Packed__c}"/>
            </div>

            <div class="slds-form-element">
                <lightning:button label="Create Camping Item"
                                  onclick="{!c.clickCreateItem}"/>
            </div>

        </form>
    </div>

</aura:component>

 

 Dear Friends,

Can Anyone explain Why this error was showing here ...

trigger ExampleTrigger on Contact (after insert, after delete) {
    if (Trigger.isInsert) {
        Integer recordCount = Trigger.New.size();
        // Call a utility method from another class
        EmailManager.sendMail('Your email address', 'Trailhead Trigger Tutorial', 
                    recordCount + ' contact(s) were inserted.');
    }
    else if (Trigger.isDelete) {
        // Process after delete
    }
}


Error : Variable does not exist: EmailManager


Thanks In Advance ..