def parse(self, declarations_str):
for decl in declarations_str.split('<STR_LIT:;>'):<EOL><INDENT>if not decl.strip():<EOL><INDENT>continue<EOL><DEDENT>prop, sep, val = decl.partition('<STR_LIT::>')<EOL>prop = prop.strip().lower()<EOL>val = val.strip().lower()<EOL>if sep:<EOL><INDENT>yield prop, val<EOL><DEDENT>else:<EOL><INDENT>warnings.warn('<STR_LIT>'<EOL>'<STR_LIT>'.format(decl=decl), CSSWarning)<EOL><DEDENT><DEDENT>
Generates (prop, value) pairs from declarations

        In a future version may generate parsed tokens from tinycss/tinycss2