code: function getNormalizedLiteral(node) {
  		if (node.type === "Literal") {
  			return node;
  		}
  
  		if (looksLikeLiteral(node)) {
  			return {
  				type: "Literal",
  				value: -node.argument.value,
  				raw: "-" + node.argument.value
  			};
  		}
  
  		return null;
  	}
docs: Attempts to derive a Literal node from nodes that are treated like literals.
  @param {ASTNode} node Node to normalize.
  @returns {ASTNode} The original node if the node is already a Literal, or a
  normalized Literal node with the negative number as the
  value if the node represents a negative number literal,
  otherwise null if the node cannot be converted to a
  normalized literal.