@staticmethod<EOL><INDENT>def find_single(decl_matcher, decls, recursive=True):<DEDENT>
answer = matcher.find(decl_matcher, decls, recursive)<EOL>if len(answer) == <NUM_LIT:1>:<EOL><INDENT>return answer[<NUM_LIT:0>]<EOL><DEDENT>
Returns a reference to the declaration, that match `decl_matcher`
defined criteria.

if a unique declaration could not be found the method will return None.

:param decl_matcher: Python callable object, that takes one argument -
    reference to a declaration
:param decls: the search scope, :class:declaration_t object or
    :class:declaration_t objects list t
:param recursive: boolean, if True, the method will run `decl_matcher`
    on the internal declarations too