src: Create a "src" object
Description
src() is the standard constructor for srcs and is.src() tests.
Usage
src(subclass, ...)is.src(x)
Arguments
- subclass
- name of subclass. "src" is an abstract base class, so you
must supply this value. - src_is automatically prepended to the
class name
 
- ...
- fields used by object. - These dots are evaluated with explicit splicing. 
- x
- object to test for "src"-ness.