Returns a stream that applies the binary operator to the stream values of the receiver. Usually, this is the result of applying a binary operator (i.e. a method with one argument) to a pattern.
Examples of binary operators are: +, -, /, *, min, max, hypot ...
| operator | 
 operator to be applied  | 
| a | 
 a pattern (or compatible pattern input)  | 
| b | 
 a pattern (or compatible pattern input)  | 
| adverb |