function createStream1( alpha, beta ) {
		return new RandomStream( alpha, beta, opts );
	}
Returns a readable stream for generating pseudorandom numbers drawn from a beta distribution.

@private
@param {PositiveNumber} alpha - first shape parameter
@param {PositiveNumber} beta - second shape parameter
@throws {TypeError} `alpha` must be a positive number
@throws {TypeError} `beta` must be a positive number
@throws {TypeError} options argument must be an object
@throws {TypeError} must provide valid options
@throws {Error} must provide a valid state
@returns {RandomStream} Stream instance