lib/content-range.js
function ContentRange(unit, range, length) {
  this.unit = unit;
  this.range = range;
  this.length = length;
  if (this.range.high && this.length && this.length <= this.range.high) {
    throw new Error('Length is less than or equal to the range');
  }
}
function ContentRange(unit, range, length) {
  this.unit = unit;
  this.range = range;
  this.length = length;
  if (this.range.high && this.length && this.length <= this.range.high) {
    throw new Error('Length is less than or equal to the range');
  }
}
function ContentRange ( unit , range , length ) { this . unit = unit ; this . range = range ; this . length = length ; if ( this . range . high && this . length && this . length <= this . range . high ) { throw new Error ( 'Length is less than or equal to the range' ) ; } }
Content-Range HTTP Header class.

@param {String} unit Usually "bytes", but can be any token; http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.12
@param {RangeSpec|String|'*'} range A RangeSpec instance, a string like '0-49' or '*' if unknown
@param {Number|'*'} length The total length of the full entity-body or '*' if this length is unknown or difficult to determine
@constructor
@throws Error
@see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.16
Content - Range HTTP Header class .