lib/constrain.js
function(str) {
    var startsWith = !_.isNull(str.match(pOpsHeadRe))
    return startsWith & cons.isLegalSentence(str)
  }
function(str) {
    var startsWith = !_.isNull(str.match(pOpsHeadRe))
    return startsWith & cons.isLegalSentence(str)
  }
function ( str ) { var startsWith = ! _ . isNull ( str . match ( pOpsHeadRe ) ) return startsWith & cons . isLegalSentence ( str ) }
Check if the string is a SHORTESTPATH|ALLSHORTESTPATHS operation string and is legal.
@private
@param  {string}  str PATH sentence.
@return {Boolean}
Check if the string is a SHORTESTPATH|ALLSHORTESTPATHS operation string and is legal .