function isLowerCase(subject) {
    var valueString = coerceToString(subject);
    return isAlpha(valueString) && valueString.toLowerCase() === valueString;
  }
Checks whether `subject` has only lower case characters.

@function isLowerCase
@static
@since 1.0.0
@memberOf Query
@param {string} [subject=''] The string to verify.
@return {boolean} Returns `true` if `subject` is lower case or `false` otherwise.
@example
v.isLowerCase('motorcycle');
// => true

v.isLowerCase('John');
// => false

v.isLowerCase('T1000');
// => false