libs/mocha/should.js
function(field, val){
        this.obj.should
            .have.property('headers').and
            .have.property(field.toLowerCase(), val);
        return this;
    }
function(field, val){
        this.obj.should
            .have.property('headers').and
            .have.property(field.toLowerCase(), val);
        return this;
    }
function ( field , val ) { this . obj . should . have . property ( 'headers' ) . and . have . property ( field . toLowerCase ( ) , val ) ; return this ; }
Assert that header `field` has the given `val`.

@param {String} field
@param {String} val
@return {Assertion} for chaining
@api public
Assert that header field has the given val .