## is_number
```mermaid
%%{init: {
'theme': 'base',
'themeVariables': {
'fontSize': '11px',
'nodePadding': '1',
'nodeBorder': '1',
'lineWidth': '0.8',
'fontFamily': 'Arial'
}
}}%%
flowchart LR
Start(( )) --> is_number
is_number -->| | IS_NUMBER
IS_NUMBER --> End(( ))
```