function extractGlamorStyles(className) {
  const glamorlessClassName = []
  const glamorStyles = []
  className
    .toString()
    .split(' ')
    .forEach(name => {
      if (styleSheet.registered[name.substring(4)] === undefined) {
        glamorlessClassName.push(name)
      } else {
        const style = buildGlamorSrcFromClassName(name)
        glamorStyles.push(style)
      }
    })

  return {glamorlessClassName, glamorStyles}
}
This function takes a className string and gets all the
associated glamor styles. It's used to merge glamor styles
from a className to make sure that specificity is not
a problem when passing a className to a component.
@param {String} [className=''] the className string
@return {Object} { glamorStyles, glamorlessClassName }
  - glamorStyles is an array of all the glamor styles objects
  - glamorlessClassName is the rest of the className string
    without the glamor classNames