setIdentifier(
		identifier,
		rootInfo,
		getMembers,
		getMembersOptionals,
		getMemberRanges
	) {
		this.type = TypeIdentifier;
		this.identifier = identifier;
		this.rootInfo = rootInfo;
		this.getMembers = getMembers;
		this.getMembersOptionals = getMembersOptionals;
		this.getMemberRanges = getMemberRanges;
		this.sideEffects = true;
		return this;
	}
Set's the value of this expression to a particular identifier and its members.
@param {string | VariableInfo} identifier identifier to set
@param {string | VariableInfo} rootInfo root info
@param {() => string[]} getMembers members
@param {() => boolean[]=} getMembersOptionals optional members
@param {() => Range[]=} getMemberRanges ranges of progressively increasing sub-expressions
@returns {this} this