How to use the @amalto/helpers.isValidKeyChar function in @amalto/helpers

private handleKeyChange = ( event: any ) => {
        if ( isValidKeyChar( event.target.value ) || !event.target.value ) {
            let idx = event.currentTarget.getAttribute( 'data-idx' )
            let keyValueStore = this.getKeyValueStore( this.props.keyValues )

            keyValueStore[idx] = {
                key: event.target.value,
                contentType: keyValueStore[idx].contentType,
                contentBytes: keyValueStore[idx].contentBytes
            }

            this.props.handleChange( this.getKeyValuesObject( keyValueStore ) )
        }
    }

private handleKeyChange = ( event: any ) => {
        if ( isValidKeyChar( event.target.value ) || !event.target.value ) {
            let idx = event.currentTarget.getAttribute( 'data-idx' )
            let keyValueStore = this.getKeyValueStore( this.props.keyValues )

            keyValueStore[idx] = {
                key: event.target.value,
                contentType: keyValueStore[idx].contentType,
                contentBytes: keyValueStore[idx].contentBytes
            }

            this.props.handleChange( this.getKeyValuesObject( keyValueStore ) )
        }
    }