to_enum

        # Enumerator::Lazy.to_enum

(from ruby core)
### Implementation from Lazy
---
    lzy.to_enum(method = :each, *args)                   -> lazy_enum
    lzy.enum_for(method = :each, *args)                  -> lazy_enum
    lzy.to_enum(method = :each, *args) {|*args| block }  -> lazy_enum
    lzy.enum_for(method = :each, *args) {|*args| block } -> lazy_enum

---

Similar to Object#to_enum, except it returns a lazy enumerator. This
makes it easy to define Enumerable methods that will naturally remain
lazy if called from a lazy enumerator.

For example, continuing from the example in Object#to_enum:

    # See Object#to_enum for the definition of repeat
    r = 1..Float::INFINITY
    r.repeat(2).first(5) # => [1, 1, 2, 2, 3]
    r.repeat(2).class # => Enumerator
    r.repeat(2).map{|n| n ** 2}.first(5) # => endless loop!
    # works naturally on lazy enumerator:
    r.lazy.repeat(2).class # => Enumerator::Lazy
    r.lazy.repeat(2).map{|n| n ** 2}.first(5) # => [1, 1, 4, 4, 9]