export class Strings { static EMPTY = '' ; static VOID = "void" ; param str static isAroundQuotation ( str ) { if ( str == undefined || str == null ) { return false ; } var beginChar = str . charCodeAt ( 0 ) ; var endChar = str . charCodeAt ( str . length - 1 ) ; return ( beginChar == endChar ) && ( beginChar == 0x22 || beginChar == 0x27 ) ; } static isString ( typeName ) { return "string" == typeName || "String" == typeName ; } param str static removeQuotation ( str ) { if ( Strings . isAroundQuotation ( str ) ) { return str . substring ( 1 , str . length - 1 ) ; } return str ; } static lowerFirstCase ( str ) { if ( str . length <= 1 ) { return str . toLowerCase ( ) ; } else { return str . substring ( 0 , 1 ) . toLowerCase ( ) + str . substring ( 1 , str . length ) ; } } } export class Verify { static verify ( expression , message ) { if ( ! expression ) { throw new Error ( message ) ; } } }