search by email

			if (query.length > 0) {

				const promises = [

					this.findAttendeesFromContactsAPI(query),

					this.findAttendeesFromDAV(query),

				]

				const [contactsResults] = await Promise.all(promises)

				const [contactsResults, davResults] = await Promise.all(promises)

				matches.push(...contactsResults)

				matches.push(...davResults)

				// Source of the Regex: https://stackoverflow.com/a/46181

				// eslint-disable-next-line

				if (!principal.email) {

					return false

				}

				if (!principal.email.includes(query)) {

					return false

				}

				if (this.alreadyInvitedEmails.includes(principal.email)) {

					return false

				}