function warnMissedAreas (areas, decl, result) {
  let missed = Object.keys(areas)

  decl.root().walkDecls('grid-area', gridArea => {
    missed = missed.filter(e => e !== gridArea.value)
  })

  if (missed.length > 0) {
    decl.warn(result, 'Can not find grid areas: ' + missed.join(', '))
  }

  return undefined
}
function warnMissedAreas (areas, decl, result) {
  let missed = Object.keys(areas)

  decl.root().walkDecls('grid-area', gridArea => {
    missed = missed.filter(e => e !== gridArea.value)
  })

  if (missed.length > 0) {
    decl.warn(result, 'Can not find grid areas: ' + missed.join(', '))
  }

  return undefined
}
function warnMissedAreas ( areas , decl , result ) { let missed = Object . keys ( areas ) decl . root ( ) . walkDecls ( 'grid-area' , gridArea => { missed = missed . filter ( e => e !== gridArea . value ) } ) if ( missed . length > 0 ) { decl . warn ( result , 'Can not find grid areas: ' + missed . join ( ', ' ) ) } return undefined }
Warn user if grid area identifiers are not found
@param  {Object} areas
@param  {Declaration} decl
@param  {Result} result
@return {void}
Warn user if grid area identifiers are not found
Warn if any grid - areas are not present in the declaration