@Beta
  public <T> T Spy() {
    throw invalidMockCreation();
  }
Creates a spy whose type and name are inferred from the left-hand side of the enclosing variable assignment.

Example:

<pre>
  Person person = Spy() // type is Person.class, name is "person"
</pre>

@return a spy whose type and name are inferred from the left-hand side of the enclosing variable assignment
spock-core/src/main/java/spock/mock/MockingApi.java